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fune/third_party/python/pyparsing/pyparsing.py
Mitchell Hentges d76d2cf32e Bug 1723031: Vendors packaging, pyparsing library r=ahal 
This will allow us to parse and compare pip package versions the same
way that `pip` does.

`pyparsing` was added because it's needed by `packaging`.

Differential Revision: https://phabricator.services.mozilla.com/D122888
2021-09-28 14:59:29 +00:00

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# -*- coding: utf-8 -*-
# module pyparsing.py
#
# Copyright (c) 2003-2019 Paul T. McGuire
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
# IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
# CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
# TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
# SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
#
__doc__ = \
"""
pyparsing module - Classes and methods to define and execute parsing grammars
=============================================================================
The pyparsing module is an alternative approach to creating and
executing simple grammars, vs. the traditional lex/yacc approach, or the
use of regular expressions. With pyparsing, you don't need to learn
a new syntax for defining grammars or matching expressions - the parsing
module provides a library of classes that you use to construct the
grammar directly in Python.
Here is a program to parse "Hello, World!" (or any greeting of the form
``"<salutation>, <addressee>!"``), built up using :class:`Word`,
:class:`Literal`, and :class:`And` elements
(the :class:`'+'<ParserElement.__add__>` operators create :class:`And` expressions,
and the strings are auto-converted to :class:`Literal` expressions)::
from pyparsing import Word, alphas
# define grammar of a greeting
greet = Word(alphas) + "," + Word(alphas) + "!"
hello = "Hello, World!"
print (hello, "->", greet.parseString(hello))
The program outputs the following::
Hello, World! -> ['Hello', ',', 'World', '!']
The Python representation of the grammar is quite readable, owing to the
self-explanatory class names, and the use of '+', '|' and '^' operators.
The :class:`ParseResults` object returned from
:class:`ParserElement.parseString` can be
accessed as a nested list, a dictionary, or an object with named
attributes.
The pyparsing module handles some of the problems that are typically
vexing when writing text parsers:
- extra or missing whitespace (the above program will also handle
"Hello,World!", "Hello , World !", etc.)
- quoted strings
- embedded comments
Getting Started -
-----------------
Visit the classes :class:`ParserElement` and :class:`ParseResults` to
see the base classes that most other pyparsing
classes inherit from. Use the docstrings for examples of how to:
- construct literal match expressions from :class:`Literal` and
:class:`CaselessLiteral` classes
- construct character word-group expressions using the :class:`Word`
class
- see how to create repetitive expressions using :class:`ZeroOrMore`
and :class:`OneOrMore` classes
- use :class:`'+'<And>`, :class:`'|'<MatchFirst>`, :class:`'^'<Or>`,
and :class:`'&'<Each>` operators to combine simple expressions into
more complex ones
- associate names with your parsed results using
:class:`ParserElement.setResultsName`
- access the parsed data, which is returned as a :class:`ParseResults`
object
- find some helpful expression short-cuts like :class:`delimitedList`
and :class:`oneOf`
- find more useful common expressions in the :class:`pyparsing_common`
namespace class
"""
__version__ = "2.4.7"
__versionTime__ = "30 Mar 2020 00:43 UTC"
__author__ = "Paul McGuire <ptmcg@users.sourceforge.net>"
import string
from weakref import ref as wkref
import copy
import sys
import warnings
import re
import sre_constants
import collections
import pprint
import traceback
import types
from datetime import datetime
from operator import itemgetter
import itertools
from functools import wraps
from contextlib import contextmanager
try:
# Python 3
from itertools import filterfalse
except ImportError:
from itertools import ifilterfalse as filterfalse
try:
from _thread import RLock
except ImportError:
from threading import RLock
try:
# Python 3
from collections.abc import Iterable
from collections.abc import MutableMapping, Mapping
except ImportError:
# Python 2.7
from collections import Iterable
from collections import MutableMapping, Mapping
try:
from collections import OrderedDict as _OrderedDict
except ImportError:
try:
from ordereddict import OrderedDict as _OrderedDict
except ImportError:
_OrderedDict = None
try:
from types import SimpleNamespace
except ImportError:
class SimpleNamespace: pass
# version compatibility configuration
__compat__ = SimpleNamespace()
__compat__.__doc__ = """
A cross-version compatibility configuration for pyparsing features that will be
released in a future version. By setting values in this configuration to True,
those features can be enabled in prior versions for compatibility development
and testing.
- collect_all_And_tokens - flag to enable fix for Issue #63 that fixes erroneous grouping
of results names when an And expression is nested within an Or or MatchFirst; set to
True to enable bugfix released in pyparsing 2.3.0, or False to preserve
pre-2.3.0 handling of named results
"""
__compat__.collect_all_And_tokens = True
__diag__ = SimpleNamespace()
__diag__.__doc__ = """
Diagnostic configuration (all default to False)
- warn_multiple_tokens_in_named_alternation - flag to enable warnings when a results
name is defined on a MatchFirst or Or expression with one or more And subexpressions
(only warns if __compat__.collect_all_And_tokens is False)
- warn_ungrouped_named_tokens_in_collection - flag to enable warnings when a results
name is defined on a containing expression with ungrouped subexpressions that also
have results names
- warn_name_set_on_empty_Forward - flag to enable warnings whan a Forward is defined
with a results name, but has no contents defined
- warn_on_multiple_string_args_to_oneof - flag to enable warnings whan oneOf is
incorrectly called with multiple str arguments
- enable_debug_on_named_expressions - flag to auto-enable debug on all subsequent
calls to ParserElement.setName()
"""
__diag__.warn_multiple_tokens_in_named_alternation = False
__diag__.warn_ungrouped_named_tokens_in_collection = False
__diag__.warn_name_set_on_empty_Forward = False
__diag__.warn_on_multiple_string_args_to_oneof = False
__diag__.enable_debug_on_named_expressions = False
__diag__._all_names = [nm for nm in vars(__diag__) if nm.startswith("enable_") or nm.startswith("warn_")]
def _enable_all_warnings():
__diag__.warn_multiple_tokens_in_named_alternation = True
__diag__.warn_ungrouped_named_tokens_in_collection = True
__diag__.warn_name_set_on_empty_Forward = True
__diag__.warn_on_multiple_string_args_to_oneof = True
__diag__.enable_all_warnings = _enable_all_warnings
__all__ = ['__version__', '__versionTime__', '__author__', '__compat__', '__diag__',
'And', 'CaselessKeyword', 'CaselessLiteral', 'CharsNotIn', 'Combine', 'Dict', 'Each', 'Empty',
'FollowedBy', 'Forward', 'GoToColumn', 'Group', 'Keyword', 'LineEnd', 'LineStart', 'Literal',
'PrecededBy', 'MatchFirst', 'NoMatch', 'NotAny', 'OneOrMore', 'OnlyOnce', 'Optional', 'Or',
'ParseBaseException', 'ParseElementEnhance', 'ParseException', 'ParseExpression', 'ParseFatalException',
'ParseResults', 'ParseSyntaxException', 'ParserElement', 'QuotedString', 'RecursiveGrammarException',
'Regex', 'SkipTo', 'StringEnd', 'StringStart', 'Suppress', 'Token', 'TokenConverter',
'White', 'Word', 'WordEnd', 'WordStart', 'ZeroOrMore', 'Char',
'alphanums', 'alphas', 'alphas8bit', 'anyCloseTag', 'anyOpenTag', 'cStyleComment', 'col',
'commaSeparatedList', 'commonHTMLEntity', 'countedArray', 'cppStyleComment', 'dblQuotedString',
'dblSlashComment', 'delimitedList', 'dictOf', 'downcaseTokens', 'empty', 'hexnums',
'htmlComment', 'javaStyleComment', 'line', 'lineEnd', 'lineStart', 'lineno',
'makeHTMLTags', 'makeXMLTags', 'matchOnlyAtCol', 'matchPreviousExpr', 'matchPreviousLiteral',
'nestedExpr', 'nullDebugAction', 'nums', 'oneOf', 'opAssoc', 'operatorPrecedence', 'printables',
'punc8bit', 'pythonStyleComment', 'quotedString', 'removeQuotes', 'replaceHTMLEntity',
'replaceWith', 'restOfLine', 'sglQuotedString', 'srange', 'stringEnd',
'stringStart', 'traceParseAction', 'unicodeString', 'upcaseTokens', 'withAttribute',
'indentedBlock', 'originalTextFor', 'ungroup', 'infixNotation', 'locatedExpr', 'withClass',
'CloseMatch', 'tokenMap', 'pyparsing_common', 'pyparsing_unicode', 'unicode_set',
'conditionAsParseAction', 're',
]
system_version = tuple(sys.version_info)[:3]
PY_3 = system_version[0] == 3
if PY_3:
_MAX_INT = sys.maxsize
basestring = str
unichr = chr
unicode = str
_ustr = str
# build list of single arg builtins, that can be used as parse actions
singleArgBuiltins = [sum, len, sorted, reversed, list, tuple, set, any, all, min, max]
else:
_MAX_INT = sys.maxint
range = xrange
def _ustr(obj):
"""Drop-in replacement for str(obj) that tries to be Unicode
friendly. It first tries str(obj). If that fails with
a UnicodeEncodeError, then it tries unicode(obj). It then
< returns the unicode object | encodes it with the default
encoding | ... >.
"""
if isinstance(obj, unicode):
return obj
try:
# If this works, then _ustr(obj) has the same behaviour as str(obj), so
# it won't break any existing code.
return str(obj)
except UnicodeEncodeError:
# Else encode it
ret = unicode(obj).encode(sys.getdefaultencoding(), 'xmlcharrefreplace')
xmlcharref = Regex(r'&#\d+;')
xmlcharref.setParseAction(lambda t: '\\u' + hex(int(t[0][2:-1]))[2:])
return xmlcharref.transformString(ret)
# build list of single arg builtins, tolerant of Python version, that can be used as parse actions
singleArgBuiltins = []
import __builtin__
for fname in "sum len sorted reversed list tuple set any all min max".split():
try:
singleArgBuiltins.append(getattr(__builtin__, fname))
except AttributeError:
continue
_generatorType = type((y for y in range(1)))
def _xml_escape(data):
"""Escape &, <, >, ", ', etc. in a string of data."""
# ampersand must be replaced first
from_symbols = '&><"\''
to_symbols = ('&' + s + ';' for s in "amp gt lt quot apos".split())
for from_, to_ in zip(from_symbols, to_symbols):
data = data.replace(from_, to_)
return data
alphas = string.ascii_uppercase + string.ascii_lowercase
nums = "0123456789"
hexnums = nums + "ABCDEFabcdef"
alphanums = alphas + nums
_bslash = chr(92)
printables = "".join(c for c in string.printable if c not in string.whitespace)
def conditionAsParseAction(fn, message=None, fatal=False):
msg = message if message is not None else "failed user-defined condition"
exc_type = ParseFatalException if fatal else ParseException
fn = _trim_arity(fn)
@wraps(fn)
def pa(s, l, t):
if not bool(fn(s, l, t)):
raise exc_type(s, l, msg)
return pa
class ParseBaseException(Exception):
"""base exception class for all parsing runtime exceptions"""
# Performance tuning: we construct a *lot* of these, so keep this
# constructor as small and fast as possible
def __init__(self, pstr, loc=0, msg=None, elem=None):
self.loc = loc
if msg is None:
self.msg = pstr
self.pstr = ""
else:
self.msg = msg
self.pstr = pstr
self.parserElement = elem
self.args = (pstr, loc, msg)
@classmethod
def _from_exception(cls, pe):
"""
internal factory method to simplify creating one type of ParseException
from another - avoids having __init__ signature conflicts among subclasses
"""
return cls(pe.pstr, pe.loc, pe.msg, pe.parserElement)
def __getattr__(self, aname):
"""supported attributes by name are:
- lineno - returns the line number of the exception text
- col - returns the column number of the exception text
- line - returns the line containing the exception text
"""
if aname == "lineno":
return lineno(self.loc, self.pstr)
elif aname in ("col", "column"):
return col(self.loc, self.pstr)
elif aname == "line":
return line(self.loc, self.pstr)
else:
raise AttributeError(aname)
def __str__(self):
if self.pstr:
if self.loc >= len(self.pstr):
foundstr = ', found end of text'
else:
foundstr = (', found %r' % self.pstr[self.loc:self.loc + 1]).replace(r'\\', '\\')
else:
foundstr = ''
return ("%s%s (at char %d), (line:%d, col:%d)" %
(self.msg, foundstr, self.loc, self.lineno, self.column))
def __repr__(self):
return _ustr(self)
def markInputline(self, markerString=">!<"):
"""Extracts the exception line from the input string, and marks
the location of the exception with a special symbol.
"""
line_str = self.line
line_column = self.column - 1
if markerString:
line_str = "".join((line_str[:line_column],
markerString, line_str[line_column:]))
return line_str.strip()
def __dir__(self):
return "lineno col line".split() + dir(type(self))
class ParseException(ParseBaseException):
"""
Exception thrown when parse expressions don't match class;
supported attributes by name are:
- lineno - returns the line number of the exception text
- col - returns the column number of the exception text
- line - returns the line containing the exception text
Example::
try:
Word(nums).setName("integer").parseString("ABC")
except ParseException as pe:
print(pe)
print("column: {}".format(pe.col))
prints::
Expected integer (at char 0), (line:1, col:1)
column: 1
"""
@staticmethod
def explain(exc, depth=16):
"""
Method to take an exception and translate the Python internal traceback into a list
of the pyparsing expressions that caused the exception to be raised.
Parameters:
- exc - exception raised during parsing (need not be a ParseException, in support
of Python exceptions that might be raised in a parse action)
- depth (default=16) - number of levels back in the stack trace to list expression
and function names; if None, the full stack trace names will be listed; if 0, only
the failing input line, marker, and exception string will be shown
Returns a multi-line string listing the ParserElements and/or function names in the
exception's stack trace.
Note: the diagnostic output will include string representations of the expressions
that failed to parse. These representations will be more helpful if you use `setName` to
give identifiable names to your expressions. Otherwise they will use the default string
forms, which may be cryptic to read.
explain() is only supported under Python 3.
"""
import inspect
if depth is None:
depth = sys.getrecursionlimit()
ret = []
if isinstance(exc, ParseBaseException):
ret.append(exc.line)
ret.append(' ' * (exc.col - 1) + '^')
ret.append("{0}: {1}".format(type(exc).__name__, exc))
if depth > 0:
callers = inspect.getinnerframes(exc.__traceback__, context=depth)
seen = set()
for i, ff in enumerate(callers[-depth:]):
frm = ff[0]
f_self = frm.f_locals.get('self', None)
if isinstance(f_self, ParserElement):
if frm.f_code.co_name not in ('parseImpl', '_parseNoCache'):
continue
if f_self in seen:
continue
seen.add(f_self)
self_type = type(f_self)
ret.append("{0}.{1} - {2}".format(self_type.__module__,
self_type.__name__,
f_self))
elif f_self is not None:
self_type = type(f_self)
ret.append("{0}.{1}".format(self_type.__module__,
self_type.__name__))
else:
code = frm.f_code
if code.co_name in ('wrapper', '<module>'):
continue
ret.append("{0}".format(code.co_name))
depth -= 1
if not depth:
break
return '\n'.join(ret)
class ParseFatalException(ParseBaseException):
"""user-throwable exception thrown when inconsistent parse content
is found; stops all parsing immediately"""
pass
class ParseSyntaxException(ParseFatalException):
"""just like :class:`ParseFatalException`, but thrown internally
when an :class:`ErrorStop<And._ErrorStop>` ('-' operator) indicates
that parsing is to stop immediately because an unbacktrackable
syntax error has been found.
"""
pass
#~ class ReparseException(ParseBaseException):
#~ """Experimental class - parse actions can raise this exception to cause
#~ pyparsing to reparse the input string:
#~ - with a modified input string, and/or
#~ - with a modified start location
#~ Set the values of the ReparseException in the constructor, and raise the
#~ exception in a parse action to cause pyparsing to use the new string/location.
#~ Setting the values as None causes no change to be made.
#~ """
#~ def __init_( self, newstring, restartLoc ):
#~ self.newParseText = newstring
#~ self.reparseLoc = restartLoc
class RecursiveGrammarException(Exception):
"""exception thrown by :class:`ParserElement.validate` if the
grammar could be improperly recursive
"""
def __init__(self, parseElementList):
self.parseElementTrace = parseElementList
def __str__(self):
return "RecursiveGrammarException: %s" % self.parseElementTrace
class _ParseResultsWithOffset(object):
def __init__(self, p1, p2):
self.tup = (p1, p2)
def __getitem__(self, i):
return self.tup[i]
def __repr__(self):
return repr(self.tup[0])
def setOffset(self, i):
self.tup = (self.tup[0], i)
class ParseResults(object):
"""Structured parse results, to provide multiple means of access to
the parsed data:
- as a list (``len(results)``)
- by list index (``results[0], results[1]``, etc.)
- by attribute (``results.<resultsName>`` - see :class:`ParserElement.setResultsName`)
Example::
integer = Word(nums)
date_str = (integer.setResultsName("year") + '/'
+ integer.setResultsName("month") + '/'
+ integer.setResultsName("day"))
# equivalent form:
# date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
# parseString returns a ParseResults object
result = date_str.parseString("1999/12/31")
def test(s, fn=repr):
print("%s -> %s" % (s, fn(eval(s))))
test("list(result)")
test("result[0]")
test("result['month']")
test("result.day")
test("'month' in result")
test("'minutes' in result")
test("result.dump()", str)
prints::
list(result) -> ['1999', '/', '12', '/', '31']
result[0] -> '1999'
result['month'] -> '12'
result.day -> '31'
'month' in result -> True
'minutes' in result -> False
result.dump() -> ['1999', '/', '12', '/', '31']
- day: 31
- month: 12
- year: 1999
"""
def __new__(cls, toklist=None, name=None, asList=True, modal=True):
if isinstance(toklist, cls):
return toklist
retobj = object.__new__(cls)
retobj.__doinit = True
return retobj
# Performance tuning: we construct a *lot* of these, so keep this
# constructor as small and fast as possible
def __init__(self, toklist=None, name=None, asList=True, modal=True, isinstance=isinstance):
if self.__doinit:
self.__doinit = False
self.__name = None
self.__parent = None
self.__accumNames = {}
self.__asList = asList
self.__modal = modal
if toklist is None:
toklist = []
if isinstance(toklist, list):
self.__toklist = toklist[:]
elif isinstance(toklist, _generatorType):
self.__toklist = list(toklist)
else:
self.__toklist = [toklist]
self.__tokdict = dict()
if name is not None and name:
if not modal:
self.__accumNames[name] = 0
if isinstance(name, int):
name = _ustr(name) # will always return a str, but use _ustr for consistency
self.__name = name
if not (isinstance(toklist, (type(None), basestring, list)) and toklist in (None, '', [])):
if isinstance(toklist, basestring):
toklist = [toklist]
if asList:
if isinstance(toklist, ParseResults):
self[name] = _ParseResultsWithOffset(ParseResults(toklist.__toklist), 0)
else:
self[name] = _ParseResultsWithOffset(ParseResults(toklist[0]), 0)
self[name].__name = name
else:
try:
self[name] = toklist[0]
except (KeyError, TypeError, IndexError):
self[name] = toklist
def __getitem__(self, i):
if isinstance(i, (int, slice)):
return self.__toklist[i]
else:
if i not in self.__accumNames:
return self.__tokdict[i][-1][0]
else:
return ParseResults([v[0] for v in self.__tokdict[i]])
def __setitem__(self, k, v, isinstance=isinstance):
if isinstance(v, _ParseResultsWithOffset):
self.__tokdict[k] = self.__tokdict.get(k, list()) + [v]
sub = v[0]
elif isinstance(k, (int, slice)):
self.__toklist[k] = v
sub = v
else:
self.__tokdict[k] = self.__tokdict.get(k, list()) + [_ParseResultsWithOffset(v, 0)]
sub = v
if isinstance(sub, ParseResults):
sub.__parent = wkref(self)
def __delitem__(self, i):
if isinstance(i, (int, slice)):
mylen = len(self.__toklist)
del self.__toklist[i]
# convert int to slice
if isinstance(i, int):
if i < 0:
i += mylen
i = slice(i, i + 1)
# get removed indices
removed = list(range(*i.indices(mylen)))
removed.reverse()
# fixup indices in token dictionary
for name, occurrences in self.__tokdict.items():
for j in removed:
for k, (value, position) in enumerate(occurrences):
occurrences[k] = _ParseResultsWithOffset(value, position - (position > j))
else:
del self.__tokdict[i]
def __contains__(self, k):
return k in self.__tokdict
def __len__(self):
return len(self.__toklist)
def __bool__(self):
return (not not self.__toklist)
__nonzero__ = __bool__
def __iter__(self):
return iter(self.__toklist)
def __reversed__(self):
return iter(self.__toklist[::-1])
def _iterkeys(self):
if hasattr(self.__tokdict, "iterkeys"):
return self.__tokdict.iterkeys()
else:
return iter(self.__tokdict)
def _itervalues(self):
return (self[k] for k in self._iterkeys())
def _iteritems(self):
return ((k, self[k]) for k in self._iterkeys())
if PY_3:
keys = _iterkeys
"""Returns an iterator of all named result keys."""
values = _itervalues
"""Returns an iterator of all named result values."""
items = _iteritems
"""Returns an iterator of all named result key-value tuples."""
else:
iterkeys = _iterkeys
"""Returns an iterator of all named result keys (Python 2.x only)."""
itervalues = _itervalues
"""Returns an iterator of all named result values (Python 2.x only)."""
iteritems = _iteritems
"""Returns an iterator of all named result key-value tuples (Python 2.x only)."""
def keys(self):
"""Returns all named result keys (as a list in Python 2.x, as an iterator in Python 3.x)."""
return list(self.iterkeys())
def values(self):
"""Returns all named result values (as a list in Python 2.x, as an iterator in Python 3.x)."""
return list(self.itervalues())
def items(self):
"""Returns all named result key-values (as a list of tuples in Python 2.x, as an iterator in Python 3.x)."""
return list(self.iteritems())
def haskeys(self):
"""Since keys() returns an iterator, this method is helpful in bypassing
code that looks for the existence of any defined results names."""
return bool(self.__tokdict)
def pop(self, *args, **kwargs):
"""
Removes and returns item at specified index (default= ``last``).
Supports both ``list`` and ``dict`` semantics for ``pop()``. If
passed no argument or an integer argument, it will use ``list``
semantics and pop tokens from the list of parsed tokens. If passed
a non-integer argument (most likely a string), it will use ``dict``
semantics and pop the corresponding value from any defined results
names. A second default return value argument is supported, just as in
``dict.pop()``.
Example::
def remove_first(tokens):
tokens.pop(0)
print(OneOrMore(Word(nums)).parseString("0 123 321")) # -> ['0', '123', '321']
print(OneOrMore(Word(nums)).addParseAction(remove_first).parseString("0 123 321")) # -> ['123', '321']
label = Word(alphas)
patt = label("LABEL") + OneOrMore(Word(nums))
print(patt.parseString("AAB 123 321").dump())
# Use pop() in a parse action to remove named result (note that corresponding value is not
# removed from list form of results)
def remove_LABEL(tokens):
tokens.pop("LABEL")
return tokens
patt.addParseAction(remove_LABEL)
print(patt.parseString("AAB 123 321").dump())
prints::
['AAB', '123', '321']
- LABEL: AAB
['AAB', '123', '321']
"""
if not args:
args = [-1]
for k, v in kwargs.items():
if k == 'default':
args = (args[0], v)
else:
raise TypeError("pop() got an unexpected keyword argument '%s'" % k)
if (isinstance(args[0], int)
or len(args) == 1
or args[0] in self):
index = args[0]
ret = self[index]
del self[index]
return ret
else:
defaultvalue = args[1]
return defaultvalue
def get(self, key, defaultValue=None):
"""
Returns named result matching the given key, or if there is no
such name, then returns the given ``defaultValue`` or ``None`` if no
``defaultValue`` is specified.
Similar to ``dict.get()``.
Example::
integer = Word(nums)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
result = date_str.parseString("1999/12/31")
print(result.get("year")) # -> '1999'
print(result.get("hour", "not specified")) # -> 'not specified'
print(result.get("hour")) # -> None
"""
if key in self:
return self[key]
else:
return defaultValue
def insert(self, index, insStr):
"""
Inserts new element at location index in the list of parsed tokens.
Similar to ``list.insert()``.
Example::
print(OneOrMore(Word(nums)).parseString("0 123 321")) # -> ['0', '123', '321']
# use a parse action to insert the parse location in the front of the parsed results
def insert_locn(locn, tokens):
tokens.insert(0, locn)
print(OneOrMore(Word(nums)).addParseAction(insert_locn).parseString("0 123 321")) # -> [0, '0', '123', '321']
"""
self.__toklist.insert(index, insStr)
# fixup indices in token dictionary
for name, occurrences in self.__tokdict.items():
for k, (value, position) in enumerate(occurrences):
occurrences[k] = _ParseResultsWithOffset(value, position + (position > index))
def append(self, item):
"""
Add single element to end of ParseResults list of elements.
Example::
print(OneOrMore(Word(nums)).parseString("0 123 321")) # -> ['0', '123', '321']
# use a parse action to compute the sum of the parsed integers, and add it to the end
def append_sum(tokens):
tokens.append(sum(map(int, tokens)))
print(OneOrMore(Word(nums)).addParseAction(append_sum).parseString("0 123 321")) # -> ['0', '123', '321', 444]
"""
self.__toklist.append(item)
def extend(self, itemseq):
"""
Add sequence of elements to end of ParseResults list of elements.
Example::
patt = OneOrMore(Word(alphas))
# use a parse action to append the reverse of the matched strings, to make a palindrome
def make_palindrome(tokens):
tokens.extend(reversed([t[::-1] for t in tokens]))
return ''.join(tokens)
print(patt.addParseAction(make_palindrome).parseString("lskdj sdlkjf lksd")) # -> 'lskdjsdlkjflksddsklfjkldsjdksl'
"""
if isinstance(itemseq, ParseResults):
self.__iadd__(itemseq)
else:
self.__toklist.extend(itemseq)
def clear(self):
"""
Clear all elements and results names.
"""
del self.__toklist[:]
self.__tokdict.clear()
def __getattr__(self, name):
try:
return self[name]
except KeyError:
return ""
def __add__(self, other):
ret = self.copy()
ret += other
return ret
def __iadd__(self, other):
if other.__tokdict:
offset = len(self.__toklist)
addoffset = lambda a: offset if a < 0 else a + offset
otheritems = other.__tokdict.items()
otherdictitems = [(k, _ParseResultsWithOffset(v[0], addoffset(v[1])))
for k, vlist in otheritems for v in vlist]
for k, v in otherdictitems:
self[k] = v
if isinstance(v[0], ParseResults):
v[0].__parent = wkref(self)
self.__toklist += other.__toklist
self.__accumNames.update(other.__accumNames)
return self
def __radd__(self, other):
if isinstance(other, int) and other == 0:
# useful for merging many ParseResults using sum() builtin
return self.copy()
else:
# this may raise a TypeError - so be it
return other + self
def __repr__(self):
return "(%s, %s)" % (repr(self.__toklist), repr(self.__tokdict))
def __str__(self):
return '[' + ', '.join(_ustr(i) if isinstance(i, ParseResults) else repr(i) for i in self.__toklist) + ']'
def _asStringList(self, sep=''):
out = []
for item in self.__toklist:
if out and sep:
out.append(sep)
if isinstance(item, ParseResults):
out += item._asStringList()
else:
out.append(_ustr(item))
return out
def asList(self):
"""
Returns the parse results as a nested list of matching tokens, all converted to strings.
Example::
patt = OneOrMore(Word(alphas))
result = patt.parseString("sldkj lsdkj sldkj")
# even though the result prints in string-like form, it is actually a pyparsing ParseResults
print(type(result), result) # -> <class 'pyparsing.ParseResults'> ['sldkj', 'lsdkj', 'sldkj']
# Use asList() to create an actual list
result_list = result.asList()
print(type(result_list), result_list) # -> <class 'list'> ['sldkj', 'lsdkj', 'sldkj']
"""
return [res.asList() if isinstance(res, ParseResults) else res for res in self.__toklist]
def asDict(self):
"""
Returns the named parse results as a nested dictionary.
Example::
integer = Word(nums)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
result = date_str.parseString('12/31/1999')
print(type(result), repr(result)) # -> <class 'pyparsing.ParseResults'> (['12', '/', '31', '/', '1999'], {'day': [('1999', 4)], 'year': [('12', 0)], 'month': [('31', 2)]})
result_dict = result.asDict()
print(type(result_dict), repr(result_dict)) # -> <class 'dict'> {'day': '1999', 'year': '12', 'month': '31'}
# even though a ParseResults supports dict-like access, sometime you just need to have a dict
import json
print(json.dumps(result)) # -> Exception: TypeError: ... is not JSON serializable
print(json.dumps(result.asDict())) # -> {"month": "31", "day": "1999", "year": "12"}
"""
if PY_3:
item_fn = self.items
else:
item_fn = self.iteritems
def toItem(obj):
if isinstance(obj, ParseResults):
if obj.haskeys():
return obj.asDict()
else:
return [toItem(v) for v in obj]
else:
return obj
return dict((k, toItem(v)) for k, v in item_fn())
def copy(self):
"""
Returns a new copy of a :class:`ParseResults` object.
"""
ret = ParseResults(self.__toklist)
ret.__tokdict = dict(self.__tokdict.items())
ret.__parent = self.__parent
ret.__accumNames.update(self.__accumNames)
ret.__name = self.__name
return ret
def asXML(self, doctag=None, namedItemsOnly=False, indent="", formatted=True):
"""
(Deprecated) Returns the parse results as XML. Tags are created for tokens and lists that have defined results names.
"""
nl = "\n"
out = []
namedItems = dict((v[1], k) for (k, vlist) in self.__tokdict.items()
for v in vlist)
nextLevelIndent = indent + " "
# collapse out indents if formatting is not desired
if not formatted:
indent = ""
nextLevelIndent = ""
nl = ""
selfTag = None
if doctag is not None:
selfTag = doctag
else:
if self.__name:
selfTag = self.__name
if not selfTag:
if namedItemsOnly:
return ""
else:
selfTag = "ITEM"
out += [nl, indent, "<", selfTag, ">"]
for i, res in enumerate(self.__toklist):
if isinstance(res, ParseResults):
if i in namedItems:
out += [res.asXML(namedItems[i],
namedItemsOnly and doctag is None,
nextLevelIndent,
formatted)]
else:
out += [res.asXML(None,
namedItemsOnly and doctag is None,
nextLevelIndent,
formatted)]
else:
# individual token, see if there is a name for it
resTag = None
if i in namedItems:
resTag = namedItems[i]
if not resTag:
if namedItemsOnly:
continue
else:
resTag = "ITEM"
xmlBodyText = _xml_escape(_ustr(res))
out += [nl, nextLevelIndent, "<", resTag, ">",
xmlBodyText,
"</", resTag, ">"]
out += [nl, indent, "</", selfTag, ">"]
return "".join(out)
def __lookup(self, sub):
for k, vlist in self.__tokdict.items():
for v, loc in vlist:
if sub is v:
return k
return None
def getName(self):
r"""
Returns the results name for this token expression. Useful when several
different expressions might match at a particular location.
Example::
integer = Word(nums)
ssn_expr = Regex(r"\d\d\d-\d\d-\d\d\d\d")
house_number_expr = Suppress('#') + Word(nums, alphanums)
user_data = (Group(house_number_expr)("house_number")
| Group(ssn_expr)("ssn")
| Group(integer)("age"))
user_info = OneOrMore(user_data)
result = user_info.parseString("22 111-22-3333 #221B")
for item in result:
print(item.getName(), ':', item[0])
prints::
age : 22
ssn : 111-22-3333
house_number : 221B
"""
if self.__name:
return self.__name
elif self.__parent:
par = self.__parent()
if par:
return par.__lookup(self)
else:
return None
elif (len(self) == 1
and len(self.__tokdict) == 1
and next(iter(self.__tokdict.values()))[0][1] in (0, -1)):
return next(iter(self.__tokdict.keys()))
else:
return None
def dump(self, indent='', full=True, include_list=True, _depth=0):
"""
Diagnostic method for listing out the contents of
a :class:`ParseResults`. Accepts an optional ``indent`` argument so
that this string can be embedded in a nested display of other data.
Example::
integer = Word(nums)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
result = date_str.parseString('12/31/1999')
print(result.dump())
prints::
['12', '/', '31', '/', '1999']
- day: 1999
- month: 31
- year: 12
"""
out = []
NL = '\n'
if include_list:
out.append(indent + _ustr(self.asList()))
else:
out.append('')
if full:
if self.haskeys():
items = sorted((str(k), v) for k, v in self.items())
for k, v in items:
if out:
out.append(NL)
out.append("%s%s- %s: " % (indent, (' ' * _depth), k))
if isinstance(v, ParseResults):
if v:
out.append(v.dump(indent=indent, full=full, include_list=include_list, _depth=_depth + 1))
else:
out.append(_ustr(v))
else:
out.append(repr(v))
elif any(isinstance(vv, ParseResults) for vv in self):
v = self
for i, vv in enumerate(v):
if isinstance(vv, ParseResults):
out.append("\n%s%s[%d]:\n%s%s%s" % (indent,
(' ' * (_depth)),
i,
indent,
(' ' * (_depth + 1)),
vv.dump(indent=indent,
full=full,
include_list=include_list,
_depth=_depth + 1)))
else:
out.append("\n%s%s[%d]:\n%s%s%s" % (indent,
(' ' * (_depth)),
i,
indent,
(' ' * (_depth + 1)),
_ustr(vv)))
return "".join(out)
def pprint(self, *args, **kwargs):
"""
Pretty-printer for parsed results as a list, using the
`pprint <https://docs.python.org/3/library/pprint.html>`_ module.
Accepts additional positional or keyword args as defined for
`pprint.pprint <https://docs.python.org/3/library/pprint.html#pprint.pprint>`_ .
Example::
ident = Word(alphas, alphanums)
num = Word(nums)
func = Forward()
term = ident | num | Group('(' + func + ')')
func <<= ident + Group(Optional(delimitedList(term)))
result = func.parseString("fna a,b,(fnb c,d,200),100")
result.pprint(width=40)
prints::
['fna',
['a',
'b',
['(', 'fnb', ['c', 'd', '200'], ')'],
'100']]
"""
pprint.pprint(self.asList(), *args, **kwargs)
# add support for pickle protocol
def __getstate__(self):
return (self.__toklist,
(self.__tokdict.copy(),
self.__parent is not None and self.__parent() or None,
self.__accumNames,
self.__name))
def __setstate__(self, state):
self.__toklist = state[0]
self.__tokdict, par, inAccumNames, self.__name = state[1]
self.__accumNames = {}
self.__accumNames.update(inAccumNames)
if par is not None:
self.__parent = wkref(par)
else:
self.__parent = None
def __getnewargs__(self):
return self.__toklist, self.__name, self.__asList, self.__modal
def __dir__(self):
return dir(type(self)) + list(self.keys())
@classmethod
def from_dict(cls, other, name=None):
"""
Helper classmethod to construct a ParseResults from a dict, preserving the
name-value relations as results names. If an optional 'name' argument is
given, a nested ParseResults will be returned
"""
def is_iterable(obj):
try:
iter(obj)
except Exception:
return False
else:
if PY_3:
return not isinstance(obj, (str, bytes))
else:
return not isinstance(obj, basestring)
ret = cls([])
for k, v in other.items():
if isinstance(v, Mapping):
ret += cls.from_dict(v, name=k)
else:
ret += cls([v], name=k, asList=is_iterable(v))
if name is not None:
ret = cls([ret], name=name)
return ret
MutableMapping.register(ParseResults)
def col (loc, strg):
"""Returns current column within a string, counting newlines as line separators.
The first column is number 1.
Note: the default parsing behavior is to expand tabs in the input string
before starting the parsing process. See
:class:`ParserElement.parseString` for more
information on parsing strings containing ``<TAB>`` s, and suggested
methods to maintain a consistent view of the parsed string, the parse
location, and line and column positions within the parsed string.
"""
s = strg
return 1 if 0 < loc < len(s) and s[loc-1] == '\n' else loc - s.rfind("\n", 0, loc)
def lineno(loc, strg):
"""Returns current line number within a string, counting newlines as line separators.
The first line is number 1.
Note - the default parsing behavior is to expand tabs in the input string
before starting the parsing process. See :class:`ParserElement.parseString`
for more information on parsing strings containing ``<TAB>`` s, and
suggested methods to maintain a consistent view of the parsed string, the
parse location, and line and column positions within the parsed string.
"""
return strg.count("\n", 0, loc) + 1
def line(loc, strg):
"""Returns the line of text containing loc within a string, counting newlines as line separators.
"""
lastCR = strg.rfind("\n", 0, loc)
nextCR = strg.find("\n", loc)
if nextCR >= 0:
return strg[lastCR + 1:nextCR]
else:
return strg[lastCR + 1:]
def _defaultStartDebugAction(instring, loc, expr):
print(("Match " + _ustr(expr) + " at loc " + _ustr(loc) + "(%d,%d)" % (lineno(loc, instring), col(loc, instring))))
def _defaultSuccessDebugAction(instring, startloc, endloc, expr, toks):
print("Matched " + _ustr(expr) + " -> " + str(toks.asList()))
def _defaultExceptionDebugAction(instring, loc, expr, exc):
print("Exception raised:" + _ustr(exc))
def nullDebugAction(*args):
"""'Do-nothing' debug action, to suppress debugging output during parsing."""
pass
# Only works on Python 3.x - nonlocal is toxic to Python 2 installs
#~ 'decorator to trim function calls to match the arity of the target'
#~ def _trim_arity(func, maxargs=3):
#~ if func in singleArgBuiltins:
#~ return lambda s,l,t: func(t)
#~ limit = 0
#~ foundArity = False
#~ def wrapper(*args):
#~ nonlocal limit,foundArity
#~ while 1:
#~ try:
#~ ret = func(*args[limit:])
#~ foundArity = True
#~ return ret
#~ except TypeError:
#~ if limit == maxargs or foundArity:
#~ raise
#~ limit += 1
#~ continue
#~ return wrapper
# this version is Python 2.x-3.x cross-compatible
'decorator to trim function calls to match the arity of the target'
def _trim_arity(func, maxargs=2):
if func in singleArgBuiltins:
return lambda s, l, t: func(t)
limit = [0]
foundArity = [False]
# traceback return data structure changed in Py3.5 - normalize back to plain tuples
if system_version[:2] >= (3, 5):
def extract_stack(limit=0):
# special handling for Python 3.5.0 - extra deep call stack by 1
offset = -3 if system_version == (3, 5, 0) else -2
frame_summary = traceback.extract_stack(limit=-offset + limit - 1)[offset]
return [frame_summary[:2]]
def extract_tb(tb, limit=0):
frames = traceback.extract_tb(tb, limit=limit)
frame_summary = frames[-1]
return [frame_summary[:2]]
else:
extract_stack = traceback.extract_stack
extract_tb = traceback.extract_tb
# synthesize what would be returned by traceback.extract_stack at the call to
# user's parse action 'func', so that we don't incur call penalty at parse time
LINE_DIFF = 6
# IF ANY CODE CHANGES, EVEN JUST COMMENTS OR BLANK LINES, BETWEEN THE NEXT LINE AND
# THE CALL TO FUNC INSIDE WRAPPER, LINE_DIFF MUST BE MODIFIED!!!!
this_line = extract_stack(limit=2)[-1]
pa_call_line_synth = (this_line[0], this_line[1] + LINE_DIFF)
def wrapper(*args):
while 1:
try:
ret = func(*args[limit[0]:])
foundArity[0] = True
return ret
except TypeError:
# re-raise TypeErrors if they did not come from our arity testing
if foundArity[0]:
raise
else:
try:
tb = sys.exc_info()[-1]
if not extract_tb(tb, limit=2)[-1][:2] == pa_call_line_synth:
raise
finally:
try:
del tb
except NameError:
pass
if limit[0] <= maxargs:
limit[0] += 1
continue
raise
# copy func name to wrapper for sensible debug output
func_name = "<parse action>"
try:
func_name = getattr(func, '__name__',
getattr(func, '__class__').__name__)
except Exception:
func_name = str(func)
wrapper.__name__ = func_name
return wrapper
class ParserElement(object):
"""Abstract base level parser element class."""
DEFAULT_WHITE_CHARS = " \n\t\r"
verbose_stacktrace = False
@staticmethod
def setDefaultWhitespaceChars(chars):
r"""
Overrides the default whitespace chars
Example::
# default whitespace chars are space, <TAB> and newline
OneOrMore(Word(alphas)).parseString("abc def\nghi jkl") # -> ['abc', 'def', 'ghi', 'jkl']
# change to just treat newline as significant
ParserElement.setDefaultWhitespaceChars(" \t")
OneOrMore(Word(alphas)).parseString("abc def\nghi jkl") # -> ['abc', 'def']
"""
ParserElement.DEFAULT_WHITE_CHARS = chars
@staticmethod
def inlineLiteralsUsing(cls):
"""
Set class to be used for inclusion of string literals into a parser.
Example::
# default literal class used is Literal
integer = Word(nums)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
date_str.parseString("1999/12/31") # -> ['1999', '/', '12', '/', '31']
# change to Suppress
ParserElement.inlineLiteralsUsing(Suppress)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
date_str.parseString("1999/12/31") # -> ['1999', '12', '31']
"""
ParserElement._literalStringClass = cls
@classmethod
def _trim_traceback(cls, tb):
while tb.tb_next:
tb = tb.tb_next
return tb
def __init__(self, savelist=False):
self.parseAction = list()
self.failAction = None
# ~ self.name = "<unknown>" # don't define self.name, let subclasses try/except upcall
self.strRepr = None
self.resultsName = None
self.saveAsList = savelist
self.skipWhitespace = True
self.whiteChars = set(ParserElement.DEFAULT_WHITE_CHARS)
self.copyDefaultWhiteChars = True
self.mayReturnEmpty = False # used when checking for left-recursion
self.keepTabs = False
self.ignoreExprs = list()
self.debug = False
self.streamlined = False
self.mayIndexError = True # used to optimize exception handling for subclasses that don't advance parse index
self.errmsg = ""
self.modalResults = True # used to mark results names as modal (report only last) or cumulative (list all)
self.debugActions = (None, None, None) # custom debug actions
self.re = None
self.callPreparse = True # used to avoid redundant calls to preParse
self.callDuringTry = False
def copy(self):
"""
Make a copy of this :class:`ParserElement`. Useful for defining
different parse actions for the same parsing pattern, using copies of
the original parse element.
Example::
integer = Word(nums).setParseAction(lambda toks: int(toks[0]))
integerK = integer.copy().addParseAction(lambda toks: toks[0] * 1024) + Suppress("K")
integerM = integer.copy().addParseAction(lambda toks: toks[0] * 1024 * 1024) + Suppress("M")
print(OneOrMore(integerK | integerM | integer).parseString("5K 100 640K 256M"))
prints::
[5120, 100, 655360, 268435456]
Equivalent form of ``expr.copy()`` is just ``expr()``::
integerM = integer().addParseAction(lambda toks: toks[0] * 1024 * 1024) + Suppress("M")
"""
cpy = copy.copy(self)
cpy.parseAction = self.parseAction[:]
cpy.ignoreExprs = self.ignoreExprs[:]
if self.copyDefaultWhiteChars:
cpy.whiteChars = ParserElement.DEFAULT_WHITE_CHARS
return cpy
def setName(self, name):
"""
Define name for this expression, makes debugging and exception messages clearer.
Example::
Word(nums).parseString("ABC") # -> Exception: Expected W:(0123...) (at char 0), (line:1, col:1)
Word(nums).setName("integer").parseString("ABC") # -> Exception: Expected integer (at char 0), (line:1, col:1)
"""
self.name = name
self.errmsg = "Expected " + self.name
if __diag__.enable_debug_on_named_expressions:
self.setDebug()
return self
def setResultsName(self, name, listAllMatches=False):
"""
Define name for referencing matching tokens as a nested attribute
of the returned parse results.
NOTE: this returns a *copy* of the original :class:`ParserElement` object;
this is so that the client can define a basic element, such as an
integer, and reference it in multiple places with different names.
You can also set results names using the abbreviated syntax,
``expr("name")`` in place of ``expr.setResultsName("name")``
- see :class:`__call__`.
Example::
date_str = (integer.setResultsName("year") + '/'
+ integer.setResultsName("month") + '/'
+ integer.setResultsName("day"))
# equivalent form:
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
"""
return self._setResultsName(name, listAllMatches)
def _setResultsName(self, name, listAllMatches=False):
newself = self.copy()
if name.endswith("*"):
name = name[:-1]
listAllMatches = True
newself.resultsName = name
newself.modalResults = not listAllMatches
return newself
def setBreak(self, breakFlag=True):
"""Method to invoke the Python pdb debugger when this element is
about to be parsed. Set ``breakFlag`` to True to enable, False to
disable.
"""
if breakFlag:
_parseMethod = self._parse
def breaker(instring, loc, doActions=True, callPreParse=True):
import pdb
# this call to pdb.set_trace() is intentional, not a checkin error
pdb.set_trace()
return _parseMethod(instring, loc, doActions, callPreParse)
breaker._originalParseMethod = _parseMethod
self._parse = breaker
else:
if hasattr(self._parse, "_originalParseMethod"):
self._parse = self._parse._originalParseMethod
return self
def setParseAction(self, *fns, **kwargs):
"""
Define one or more actions to perform when successfully matching parse element definition.
Parse action fn is a callable method with 0-3 arguments, called as ``fn(s, loc, toks)`` ,
``fn(loc, toks)`` , ``fn(toks)`` , or just ``fn()`` , where:
- s = the original string being parsed (see note below)
- loc = the location of the matching substring
- toks = a list of the matched tokens, packaged as a :class:`ParseResults` object
If the functions in fns modify the tokens, they can return them as the return
value from fn, and the modified list of tokens will replace the original.
Otherwise, fn does not need to return any value.
If None is passed as the parse action, all previously added parse actions for this
expression are cleared.
Optional keyword arguments:
- callDuringTry = (default= ``False``) indicate if parse action should be run during lookaheads and alternate testing
Note: the default parsing behavior is to expand tabs in the input string
before starting the parsing process. See :class:`parseString for more
information on parsing strings containing ``<TAB>`` s, and suggested
methods to maintain a consistent view of the parsed string, the parse
location, and line and column positions within the parsed string.
Example::
integer = Word(nums)
date_str = integer + '/' + integer + '/' + integer
date_str.parseString("1999/12/31") # -> ['1999', '/', '12', '/', '31']
# use parse action to convert to ints at parse time
integer = Word(nums).setParseAction(lambda toks: int(toks[0]))
date_str = integer + '/' + integer + '/' + integer
# note that integer fields are now ints, not strings
date_str.parseString("1999/12/31") # -> [1999, '/', 12, '/', 31]
"""
if list(fns) == [None,]:
self.parseAction = []
else:
if not all(callable(fn) for fn in fns):
raise TypeError("parse actions must be callable")
self.parseAction = list(map(_trim_arity, list(fns)))
self.callDuringTry = kwargs.get("callDuringTry", False)
return self
def addParseAction(self, *fns, **kwargs):
"""
Add one or more parse actions to expression's list of parse actions. See :class:`setParseAction`.
See examples in :class:`copy`.
"""
self.parseAction += list(map(_trim_arity, list(fns)))
self.callDuringTry = self.callDuringTry or kwargs.get("callDuringTry", False)
return self
def addCondition(self, *fns, **kwargs):
"""Add a boolean predicate function to expression's list of parse actions. See
:class:`setParseAction` for function call signatures. Unlike ``setParseAction``,
functions passed to ``addCondition`` need to return boolean success/fail of the condition.
Optional keyword arguments:
- message = define a custom message to be used in the raised exception
- fatal = if True, will raise ParseFatalException to stop parsing immediately; otherwise will raise ParseException
Example::
integer = Word(nums).setParseAction(lambda toks: int(toks[0]))
year_int = integer.copy()
year_int.addCondition(lambda toks: toks[0] >= 2000, message="Only support years 2000 and later")
date_str = year_int + '/' + integer + '/' + integer
result = date_str.parseString("1999/12/31") # -> Exception: Only support years 2000 and later (at char 0), (line:1, col:1)
"""
for fn in fns:
self.parseAction.append(conditionAsParseAction(fn, message=kwargs.get('message'),
fatal=kwargs.get('fatal', False)))
self.callDuringTry = self.callDuringTry or kwargs.get("callDuringTry", False)
return self
def setFailAction(self, fn):
"""Define action to perform if parsing fails at this expression.
Fail acton fn is a callable function that takes the arguments
``fn(s, loc, expr, err)`` where:
- s = string being parsed
- loc = location where expression match was attempted and failed
- expr = the parse expression that failed
- err = the exception thrown
The function returns no value. It may throw :class:`ParseFatalException`
if it is desired to stop parsing immediately."""
self.failAction = fn
return self
def _skipIgnorables(self, instring, loc):
exprsFound = True
while exprsFound:
exprsFound = False
for e in self.ignoreExprs:
try:
while 1:
loc, dummy = e._parse(instring, loc)
exprsFound = True
except ParseException:
pass
return loc
def preParse(self, instring, loc):
if self.ignoreExprs:
loc = self._skipIgnorables(instring, loc)
if self.skipWhitespace:
wt = self.whiteChars
instrlen = len(instring)
while loc < instrlen and instring[loc] in wt:
loc += 1
return loc
def parseImpl(self, instring, loc, doActions=True):
return loc, []
def postParse(self, instring, loc, tokenlist):
return tokenlist
# ~ @profile
def _parseNoCache(self, instring, loc, doActions=True, callPreParse=True):
TRY, MATCH, FAIL = 0, 1, 2
debugging = (self.debug) # and doActions)
if debugging or self.failAction:
# ~ print ("Match", self, "at loc", loc, "(%d, %d)" % (lineno(loc, instring), col(loc, instring)))
if self.debugActions[TRY]:
self.debugActions[TRY](instring, loc, self)
try:
if callPreParse and self.callPreparse:
preloc = self.preParse(instring, loc)
else:
preloc = loc
tokensStart = preloc
if self.mayIndexError or preloc >= len(instring):
try:
loc, tokens = self.parseImpl(instring, preloc, doActions)
except IndexError:
raise ParseException(instring, len(instring), self.errmsg, self)
else:
loc, tokens = self.parseImpl(instring, preloc, doActions)
except Exception as err:
# ~ print ("Exception raised:", err)
if self.debugActions[FAIL]:
self.debugActions[FAIL](instring, tokensStart, self, err)
if self.failAction:
self.failAction(instring, tokensStart, self, err)
raise
else:
if callPreParse and self.callPreparse:
preloc = self.preParse(instring, loc)
else:
preloc = loc
tokensStart = preloc
if self.mayIndexError or preloc >= len(instring):
try:
loc, tokens = self.parseImpl(instring, preloc, doActions)
except IndexError:
raise ParseException(instring, len(instring), self.errmsg, self)
else:
loc, tokens = self.parseImpl(instring, preloc, doActions)
tokens = self.postParse(instring, loc, tokens)
retTokens = ParseResults(tokens, self.resultsName, asList=self.saveAsList, modal=self.modalResults)
if self.parseAction and (doActions or self.callDuringTry):
if debugging:
try:
for fn in self.parseAction:
try:
tokens = fn(instring, tokensStart, retTokens)
except IndexError as parse_action_exc:
exc = ParseException("exception raised in parse action")
exc.__cause__ = parse_action_exc
raise exc
if tokens is not None and tokens is not retTokens:
retTokens = ParseResults(tokens,
self.resultsName,
asList=self.saveAsList and isinstance(tokens, (ParseResults, list)),
modal=self.modalResults)
except Exception as err:
# ~ print "Exception raised in user parse action:", err
if self.debugActions[FAIL]:
self.debugActions[FAIL](instring, tokensStart, self, err)
raise
else:
for fn in self.parseAction:
try:
tokens = fn(instring, tokensStart, retTokens)
except IndexError as parse_action_exc:
exc = ParseException("exception raised in parse action")
exc.__cause__ = parse_action_exc
raise exc
if tokens is not None and tokens is not retTokens:
retTokens = ParseResults(tokens,
self.resultsName,
asList=self.saveAsList and isinstance(tokens, (ParseResults, list)),
modal=self.modalResults)
if debugging:
# ~ print ("Matched", self, "->", retTokens.asList())
if self.debugActions[MATCH]:
self.debugActions[MATCH](instring, tokensStart, loc, self, retTokens)
return loc, retTokens
def tryParse(self, instring, loc):
try:
return self._parse(instring, loc, doActions=False)[0]
except ParseFatalException:
raise ParseException(instring, loc, self.errmsg, self)
def canParseNext(self, instring, loc):
try:
self.tryParse(instring, loc)
except (ParseException, IndexError):
return False
else:
return True
class _UnboundedCache(object):
def __init__(self):
cache = {}
self.not_in_cache = not_in_cache = object()
def get(self, key):
return cache.get(key, not_in_cache)
def set(self, key, value):
cache[key] = value
def clear(self):
cache.clear()
def cache_len(self):
return len(cache)
self.get = types.MethodType(get, self)
self.set = types.MethodType(set, self)
self.clear = types.MethodType(clear, self)
self.__len__ = types.MethodType(cache_len, self)
if _OrderedDict is not None:
class _FifoCache(object):
def __init__(self, size):
self.not_in_cache = not_in_cache = object()
cache = _OrderedDict()
def get(self, key):
return cache.get(key, not_in_cache)
def set(self, key, value):
cache[key] = value
while len(cache) > size:
try:
cache.popitem(False)
except KeyError:
pass
def clear(self):
cache.clear()
def cache_len(self):
return len(cache)
self.get = types.MethodType(get, self)
self.set = types.MethodType(set, self)
self.clear = types.MethodType(clear, self)
self.__len__ = types.MethodType(cache_len, self)
else:
class _FifoCache(object):
def __init__(self, size):
self.not_in_cache = not_in_cache = object()
cache = {}
key_fifo = collections.deque([], size)
def get(self, key):
return cache.get(key, not_in_cache)
def set(self, key, value):
cache[key] = value
while len(key_fifo) > size:
cache.pop(key_fifo.popleft(), None)
key_fifo.append(key)
def clear(self):
cache.clear()
key_fifo.clear()
def cache_len(self):
return len(cache)
self.get = types.MethodType(get, self)
self.set = types.MethodType(set, self)
self.clear = types.MethodType(clear, self)
self.__len__ = types.MethodType(cache_len, self)
# argument cache for optimizing repeated calls when backtracking through recursive expressions
packrat_cache = {} # this is set later by enabledPackrat(); this is here so that resetCache() doesn't fail
packrat_cache_lock = RLock()
packrat_cache_stats = [0, 0]
# this method gets repeatedly called during backtracking with the same arguments -
# we can cache these arguments and save ourselves the trouble of re-parsing the contained expression
def _parseCache(self, instring, loc, doActions=True, callPreParse=True):
HIT, MISS = 0, 1
lookup = (self, instring, loc, callPreParse, doActions)
with ParserElement.packrat_cache_lock:
cache = ParserElement.packrat_cache
value = cache.get(lookup)
if value is cache.not_in_cache:
ParserElement.packrat_cache_stats[MISS] += 1
try:
value = self._parseNoCache(instring, loc, doActions, callPreParse)
except ParseBaseException as pe:
# cache a copy of the exception, without the traceback
cache.set(lookup, pe.__class__(*pe.args))
raise
else:
cache.set(lookup, (value[0], value[1].copy()))
return value
else:
ParserElement.packrat_cache_stats[HIT] += 1
if isinstance(value, Exception):
raise value
return value[0], value[1].copy()
_parse = _parseNoCache
@staticmethod
def resetCache():
ParserElement.packrat_cache.clear()
ParserElement.packrat_cache_stats[:] = [0] * len(ParserElement.packrat_cache_stats)
_packratEnabled = False
@staticmethod
def enablePackrat(cache_size_limit=128):
"""Enables "packrat" parsing, which adds memoizing to the parsing logic.
Repeated parse attempts at the same string location (which happens
often in many complex grammars) can immediately return a cached value,
instead of re-executing parsing/validating code. Memoizing is done of
both valid results and parsing exceptions.
Parameters:
- cache_size_limit - (default= ``128``) - if an integer value is provided
will limit the size of the packrat cache; if None is passed, then
the cache size will be unbounded; if 0 is passed, the cache will
be effectively disabled.
This speedup may break existing programs that use parse actions that
have side-effects. For this reason, packrat parsing is disabled when
you first import pyparsing. To activate the packrat feature, your
program must call the class method :class:`ParserElement.enablePackrat`.
For best results, call ``enablePackrat()`` immediately after
importing pyparsing.
Example::
import pyparsing
pyparsing.ParserElement.enablePackrat()
"""
if not ParserElement._packratEnabled:
ParserElement._packratEnabled = True
if cache_size_limit is None:
ParserElement.packrat_cache = ParserElement._UnboundedCache()
else:
ParserElement.packrat_cache = ParserElement._FifoCache(cache_size_limit)
ParserElement._parse = ParserElement._parseCache
def parseString(self, instring, parseAll=False):
"""
Execute the parse expression with the given string.
This is the main interface to the client code, once the complete
expression has been built.
Returns the parsed data as a :class:`ParseResults` object, which may be
accessed as a list, or as a dict or object with attributes if the given parser
includes results names.
If you want the grammar to require that the entire input string be
successfully parsed, then set ``parseAll`` to True (equivalent to ending
the grammar with ``StringEnd()``).
Note: ``parseString`` implicitly calls ``expandtabs()`` on the input string,
in order to report proper column numbers in parse actions.
If the input string contains tabs and
the grammar uses parse actions that use the ``loc`` argument to index into the
string being parsed, you can ensure you have a consistent view of the input
string by:
- calling ``parseWithTabs`` on your grammar before calling ``parseString``
(see :class:`parseWithTabs`)
- define your parse action using the full ``(s, loc, toks)`` signature, and
reference the input string using the parse action's ``s`` argument
- explictly expand the tabs in your input string before calling
``parseString``
Example::
Word('a').parseString('aaaaabaaa') # -> ['aaaaa']
Word('a').parseString('aaaaabaaa', parseAll=True) # -> Exception: Expected end of text
"""
ParserElement.resetCache()
if not self.streamlined:
self.streamline()
# ~ self.saveAsList = True
for e in self.ignoreExprs:
e.streamline()
if not self.keepTabs:
instring = instring.expandtabs()
try:
loc, tokens = self._parse(instring, 0)
if parseAll:
loc = self.preParse(instring, loc)
se = Empty() + StringEnd()
se._parse(instring, loc)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clearing out pyparsing internal stack trace
if getattr(exc, '__traceback__', None) is not None:
exc.__traceback__ = self._trim_traceback(exc.__traceback__)
raise exc
else:
return tokens
def scanString(self, instring, maxMatches=_MAX_INT, overlap=False):
"""
Scan the input string for expression matches. Each match will return the
matching tokens, start location, and end location. May be called with optional
``maxMatches`` argument, to clip scanning after 'n' matches are found. If
``overlap`` is specified, then overlapping matches will be reported.
Note that the start and end locations are reported relative to the string
being parsed. See :class:`parseString` for more information on parsing
strings with embedded tabs.
Example::
source = "sldjf123lsdjjkf345sldkjf879lkjsfd987"
print(source)
for tokens, start, end in Word(alphas).scanString(source):
print(' '*start + '^'*(end-start))
print(' '*start + tokens[0])
prints::
sldjf123lsdjjkf345sldkjf879lkjsfd987
^^^^^
sldjf
^^^^^^^
lsdjjkf
^^^^^^
sldkjf
^^^^^^
lkjsfd
"""
if not self.streamlined:
self.streamline()
for e in self.ignoreExprs:
e.streamline()
if not self.keepTabs:
instring = _ustr(instring).expandtabs()
instrlen = len(instring)
loc = 0
preparseFn = self.preParse
parseFn = self._parse
ParserElement.resetCache()
matches = 0
try:
while loc <= instrlen and matches < maxMatches:
try:
preloc = preparseFn(instring, loc)
nextLoc, tokens = parseFn(instring, preloc, callPreParse=False)
except ParseException:
loc = preloc + 1
else:
if nextLoc > loc:
matches += 1
yield tokens, preloc, nextLoc
if overlap:
nextloc = preparseFn(instring, loc)
if nextloc > loc:
loc = nextLoc
else:
loc += 1
else:
loc = nextLoc
else:
loc = preloc + 1
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clearing out pyparsing internal stack trace
if getattr(exc, '__traceback__', None) is not None:
exc.__traceback__ = self._trim_traceback(exc.__traceback__)
raise exc
def transformString(self, instring):
"""
Extension to :class:`scanString`, to modify matching text with modified tokens that may
be returned from a parse action. To use ``transformString``, define a grammar and
attach a parse action to it that modifies the returned token list.
Invoking ``transformString()`` on a target string will then scan for matches,
and replace the matched text patterns according to the logic in the parse
action. ``transformString()`` returns the resulting transformed string.
Example::
wd = Word(alphas)
wd.setParseAction(lambda toks: toks[0].title())
print(wd.transformString("now is the winter of our discontent made glorious summer by this sun of york."))
prints::
Now Is The Winter Of Our Discontent Made Glorious Summer By This Sun Of York.
"""
out = []
lastE = 0
# force preservation of <TAB>s, to minimize unwanted transformation of string, and to
# keep string locs straight between transformString and scanString
self.keepTabs = True
try:
for t, s, e in self.scanString(instring):
out.append(instring[lastE:s])
if t:
if isinstance(t, ParseResults):
out += t.asList()
elif isinstance(t, list):
out += t
else:
out.append(t)
lastE = e
out.append(instring[lastE:])
out = [o for o in out if o]
return "".join(map(_ustr, _flatten(out)))
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clearing out pyparsing internal stack trace
if getattr(exc, '__traceback__', None) is not None:
exc.__traceback__ = self._trim_traceback(exc.__traceback__)
raise exc
def searchString(self, instring, maxMatches=_MAX_INT):
"""
Another extension to :class:`scanString`, simplifying the access to the tokens found
to match the given parse expression. May be called with optional
``maxMatches`` argument, to clip searching after 'n' matches are found.
Example::
# a capitalized word starts with an uppercase letter, followed by zero or more lowercase letters
cap_word = Word(alphas.upper(), alphas.lower())
print(cap_word.searchString("More than Iron, more than Lead, more than Gold I need Electricity"))
# the sum() builtin can be used to merge results into a single ParseResults object
print(sum(cap_word.searchString("More than Iron, more than Lead, more than Gold I need Electricity")))
prints::
[['More'], ['Iron'], ['Lead'], ['Gold'], ['I'], ['Electricity']]
['More', 'Iron', 'Lead', 'Gold', 'I', 'Electricity']
"""
try:
return ParseResults([t for t, s, e in self.scanString(instring, maxMatches)])
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clearing out pyparsing internal stack trace
if getattr(exc, '__traceback__', None) is not None:
exc.__traceback__ = self._trim_traceback(exc.__traceback__)
raise exc
def split(self, instring, maxsplit=_MAX_INT, includeSeparators=False):
"""
Generator method to split a string using the given expression as a separator.
May be called with optional ``maxsplit`` argument, to limit the number of splits;
and the optional ``includeSeparators`` argument (default= ``False``), if the separating
matching text should be included in the split results.
Example::
punc = oneOf(list(".,;:/-!?"))
print(list(punc.split("This, this?, this sentence, is badly punctuated!")))
prints::
['This', ' this', '', ' this sentence', ' is badly punctuated', '']
"""
splits = 0
last = 0
for t, s, e in self.scanString(instring, maxMatches=maxsplit):
yield instring[last:s]
if includeSeparators:
yield t[0]
last = e
yield instring[last:]
def __add__(self, other):
"""
Implementation of + operator - returns :class:`And`. Adding strings to a ParserElement
converts them to :class:`Literal`s by default.
Example::
greet = Word(alphas) + "," + Word(alphas) + "!"
hello = "Hello, World!"
print (hello, "->", greet.parseString(hello))
prints::
Hello, World! -> ['Hello', ',', 'World', '!']
``...`` may be used as a parse expression as a short form of :class:`SkipTo`.
Literal('start') + ... + Literal('end')
is equivalent to:
Literal('start') + SkipTo('end')("_skipped*") + Literal('end')
Note that the skipped text is returned with '_skipped' as a results name,
and to support having multiple skips in the same parser, the value returned is
a list of all skipped text.
"""
if other is Ellipsis:
return _PendingSkip(self)
if isinstance(other, basestring):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
warnings.warn("Cannot combine element of type %s with ParserElement" % type(other),
SyntaxWarning, stacklevel=2)
return None
return And([self, other])
def __radd__(self, other):
"""
Implementation of + operator when left operand is not a :class:`ParserElement`
"""
if other is Ellipsis:
return SkipTo(self)("_skipped*") + self
if isinstance(other, basestring):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
warnings.warn("Cannot combine element of type %s with ParserElement" % type(other),
SyntaxWarning, stacklevel=2)
return None
return other + self
def __sub__(self, other):
"""
Implementation of - operator, returns :class:`And` with error stop
"""
if isinstance(other, basestring):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
warnings.warn("Cannot combine element of type %s with ParserElement" % type(other),
SyntaxWarning, stacklevel=2)
return None
return self + And._ErrorStop() + other
def __rsub__(self, other):
"""
Implementation of - operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, basestring):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
warnings.warn("Cannot combine element of type %s with ParserElement" % type(other),
SyntaxWarning, stacklevel=2)
return None
return other - self
def __mul__(self, other):
"""
Implementation of * operator, allows use of ``expr * 3`` in place of
``expr + expr + expr``. Expressions may also me multiplied by a 2-integer
tuple, similar to ``{min, max}`` multipliers in regular expressions. Tuples
may also include ``None`` as in:
- ``expr*(n, None)`` or ``expr*(n, )`` is equivalent
to ``expr*n + ZeroOrMore(expr)``
(read as "at least n instances of ``expr``")
- ``expr*(None, n)`` is equivalent to ``expr*(0, n)``
(read as "0 to n instances of ``expr``")
- ``expr*(None, None)`` is equivalent to ``ZeroOrMore(expr)``
- ``expr*(1, None)`` is equivalent to ``OneOrMore(expr)``
Note that ``expr*(None, n)`` does not raise an exception if
more than n exprs exist in the input stream; that is,
``expr*(None, n)`` does not enforce a maximum number of expr
occurrences. If this behavior is desired, then write
``expr*(None, n) + ~expr``
"""
if other is Ellipsis:
other = (0, None)
elif isinstance(other, tuple) and other[:1] == (Ellipsis,):
other = ((0, ) + other[1:] + (None,))[:2]
if isinstance(other, int):
minElements, optElements = other, 0
elif isinstance(other, tuple):
other = tuple(o if o is not Ellipsis else None for o in other)
other = (other + (None, None))[:2]
if other[0] is None:
other = (0, other[1])
if isinstance(other[0], int) and other[1] is None:
if other[0] == 0:
return ZeroOrMore(self)
if other[0] == 1:
return OneOrMore(self)
else:
return self * other[0] + ZeroOrMore(self)
elif isinstance(other[0], int) and isinstance(other[1], int):
minElements, optElements = other
optElements -= minElements
else:
raise TypeError("cannot multiply 'ParserElement' and ('%s', '%s') objects", type(other[0]), type(other[1]))
else:
raise TypeError("cannot multiply 'ParserElement' and '%s' objects", type(other))
if minElements < 0:
raise ValueError("cannot multiply ParserElement by negative value")
if optElements < 0:
raise ValueError("second tuple value must be greater or equal to first tuple value")
if minElements == optElements == 0:
raise ValueError("cannot multiply ParserElement by 0 or (0, 0)")
if optElements:
def makeOptionalList(n):
if n > 1:
return Optional(self + makeOptionalList(n - 1))
else:
return Optional(self)
if minElements:
if minElements == 1:
ret = self + makeOptionalList(optElements)
else:
ret = And([self] * minElements) + makeOptionalList(optElements)
else:
ret = makeOptionalList(optElements)
else:
if minElements == 1:
ret = self
else:
ret = And([self] * minElements)
return ret
def __rmul__(self, other):
return self.__mul__(other)
def __or__(self, other):
"""
Implementation of | operator - returns :class:`MatchFirst`
"""
if other is Ellipsis:
return _PendingSkip(self, must_skip=True)
if isinstance(other, basestring):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
warnings.warn("Cannot combine element of type %s with ParserElement" % type(other),
SyntaxWarning, stacklevel=2)
return None
return MatchFirst([self, other])
def __ror__(self, other):
"""
Implementation of | operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, basestring):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
warnings.warn("Cannot combine element of type %s with ParserElement" % type(other),
SyntaxWarning, stacklevel=2)
return None
return other | self
def __xor__(self, other):
"""
Implementation of ^ operator - returns :class:`Or`
"""
if isinstance(other, basestring):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
warnings.warn("Cannot combine element of type %s with ParserElement" % type(other),
SyntaxWarning, stacklevel=2)
return None
return Or([self, other])
def __rxor__(self, other):
"""
Implementation of ^ operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, basestring):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
warnings.warn("Cannot combine element of type %s with ParserElement" % type(other),
SyntaxWarning, stacklevel=2)
return None
return other ^ self
def __and__(self, other):
"""
Implementation of & operator - returns :class:`Each`
"""
if isinstance(other, basestring):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
warnings.warn("Cannot combine element of type %s with ParserElement" % type(other),
SyntaxWarning, stacklevel=2)
return None
return Each([self, other])
def __rand__(self, other):
"""
Implementation of & operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, basestring):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
warnings.warn("Cannot combine element of type %s with ParserElement" % type(other),
SyntaxWarning, stacklevel=2)
return None
return other & self
def __invert__(self):
"""
Implementation of ~ operator - returns :class:`NotAny`
"""
return NotAny(self)
def __iter__(self):
# must implement __iter__ to override legacy use of sequential access to __getitem__ to
# iterate over a sequence
raise TypeError('%r object is not iterable' % self.__class__.__name__)
def __getitem__(self, key):
"""
use ``[]`` indexing notation as a short form for expression repetition:
- ``expr[n]`` is equivalent to ``expr*n``
- ``expr[m, n]`` is equivalent to ``expr*(m, n)``
- ``expr[n, ...]`` or ``expr[n,]`` is equivalent
to ``expr*n + ZeroOrMore(expr)``
(read as "at least n instances of ``expr``")
- ``expr[..., n]`` is equivalent to ``expr*(0, n)``
(read as "0 to n instances of ``expr``")
- ``expr[...]`` and ``expr[0, ...]`` are equivalent to ``ZeroOrMore(expr)``
- ``expr[1, ...]`` is equivalent to ``OneOrMore(expr)``
``None`` may be used in place of ``...``.
Note that ``expr[..., n]`` and ``expr[m, n]``do not raise an exception
if more than ``n`` ``expr``s exist in the input stream. If this behavior is
desired, then write ``expr[..., n] + ~expr``.
"""
# convert single arg keys to tuples
try:
if isinstance(key, str):
key = (key,)
iter(key)
except TypeError:
key = (key, key)
if len(key) > 2:
warnings.warn("only 1 or 2 index arguments supported ({0}{1})".format(key[:5],
'... [{0}]'.format(len(key))
if len(key) > 5 else ''))
# clip to 2 elements
ret = self * tuple(key[:2])
return ret
def __call__(self, name=None):
"""
Shortcut for :class:`setResultsName`, with ``listAllMatches=False``.
If ``name`` is given with a trailing ``'*'`` character, then ``listAllMatches`` will be
passed as ``True``.
If ``name` is omitted, same as calling :class:`copy`.
Example::
# these are equivalent
userdata = Word(alphas).setResultsName("name") + Word(nums + "-").setResultsName("socsecno")
userdata = Word(alphas)("name") + Word(nums + "-")("socsecno")
"""
if name is not None:
return self._setResultsName(name)
else:
return self.copy()
def suppress(self):
"""
Suppresses the output of this :class:`ParserElement`; useful to keep punctuation from
cluttering up returned output.
"""
return Suppress(self)
def leaveWhitespace(self):
"""
Disables the skipping of whitespace before matching the characters in the
:class:`ParserElement`'s defined pattern. This is normally only used internally by
the pyparsing module, but may be needed in some whitespace-sensitive grammars.
"""
self.skipWhitespace = False
return self
def setWhitespaceChars(self, chars):
"""
Overrides the default whitespace chars
"""
self.skipWhitespace = True
self.whiteChars = chars
self.copyDefaultWhiteChars = False
return self
def parseWithTabs(self):
"""
Overrides default behavior to expand ``<TAB>``s to spaces before parsing the input string.
Must be called before ``parseString`` when the input grammar contains elements that
match ``<TAB>`` characters.
"""
self.keepTabs = True
return self
def ignore(self, other):
"""
Define expression to be ignored (e.g., comments) while doing pattern
matching; may be called repeatedly, to define multiple comment or other
ignorable patterns.
Example::
patt = OneOrMore(Word(alphas))
patt.parseString('ablaj /* comment */ lskjd') # -> ['ablaj']
patt.ignore(cStyleComment)
patt.parseString('ablaj /* comment */ lskjd') # -> ['ablaj', 'lskjd']
"""
if isinstance(other, basestring):
other = Suppress(other)
if isinstance(other, Suppress):
if other not in self.ignoreExprs:
self.ignoreExprs.append(other)
else:
self.ignoreExprs.append(Suppress(other.copy()))
return self
def setDebugActions(self, startAction, successAction, exceptionAction):
"""
Enable display of debugging messages while doing pattern matching.
"""
self.debugActions = (startAction or _defaultStartDebugAction,
successAction or _defaultSuccessDebugAction,
exceptionAction or _defaultExceptionDebugAction)
self.debug = True
return self
def setDebug(self, flag=True):
"""
Enable display of debugging messages while doing pattern matching.
Set ``flag`` to True to enable, False to disable.
Example::
wd = Word(alphas).setName("alphaword")
integer = Word(nums).setName("numword")
term = wd | integer
# turn on debugging for wd
wd.setDebug()
OneOrMore(term).parseString("abc 123 xyz 890")
prints::
Match alphaword at loc 0(1,1)
Matched alphaword -> ['abc']
Match alphaword at loc 3(1,4)
Exception raised:Expected alphaword (at char 4), (line:1, col:5)
Match alphaword at loc 7(1,8)
Matched alphaword -> ['xyz']
Match alphaword at loc 11(1,12)
Exception raised:Expected alphaword (at char 12), (line:1, col:13)
Match alphaword at loc 15(1,16)
Exception raised:Expected alphaword (at char 15), (line:1, col:16)
The output shown is that produced by the default debug actions - custom debug actions can be
specified using :class:`setDebugActions`. Prior to attempting
to match the ``wd`` expression, the debugging message ``"Match <exprname> at loc <n>(<line>,<col>)"``
is shown. Then if the parse succeeds, a ``"Matched"`` message is shown, or an ``"Exception raised"``
message is shown. Also note the use of :class:`setName` to assign a human-readable name to the expression,
which makes debugging and exception messages easier to understand - for instance, the default
name created for the :class:`Word` expression without calling ``setName`` is ``"W:(ABCD...)"``.
"""
if flag:
self.setDebugActions(_defaultStartDebugAction, _defaultSuccessDebugAction, _defaultExceptionDebugAction)
else:
self.debug = False
return self
def __str__(self):
return self.name
def __repr__(self):
return _ustr(self)
def streamline(self):
self.streamlined = True
self.strRepr = None
return self
def checkRecursion(self, parseElementList):
pass
def validate(self, validateTrace=None):
"""
Check defined expressions for valid structure, check for infinite recursive definitions.
"""
self.checkRecursion([])
def parseFile(self, file_or_filename, parseAll=False):
"""
Execute the parse expression on the given file or filename.
If a filename is specified (instead of a file object),
the entire file is opened, read, and closed before parsing.
"""
try:
file_contents = file_or_filename.read()
except AttributeError:
with open(file_or_filename, "r") as f:
file_contents = f.read()
try:
return self.parseString(file_contents, parseAll)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clearing out pyparsing internal stack trace
if getattr(exc, '__traceback__', None) is not None:
exc.__traceback__ = self._trim_traceback(exc.__traceback__)
raise exc
def __eq__(self, other):
if self is other:
return True
elif isinstance(other, basestring):
return self.matches(other)
elif isinstance(other, ParserElement):
return vars(self) == vars(other)
return False
def __ne__(self, other):
return not (self == other)
def __hash__(self):
return id(self)
def __req__(self, other):
return self == other
def __rne__(self, other):
return not (self == other)
def matches(self, testString, parseAll=True):
"""
Method for quick testing of a parser against a test string. Good for simple
inline microtests of sub expressions while building up larger parser.
Parameters:
- testString - to test against this expression for a match
- parseAll - (default= ``True``) - flag to pass to :class:`parseString` when running tests
Example::
expr = Word(nums)
assert expr.matches("100")
"""
try:
self.parseString(_ustr(testString), parseAll=parseAll)
return True
except ParseBaseException:
return False
def runTests(self, tests, parseAll=True, comment='#',
fullDump=True, printResults=True, failureTests=False, postParse=None,
file=None):
"""
Execute the parse expression on a series of test strings, showing each
test, the parsed results or where the parse failed. Quick and easy way to
run a parse expression against a list of sample strings.
Parameters:
- tests - a list of separate test strings, or a multiline string of test strings
- parseAll - (default= ``True``) - flag to pass to :class:`parseString` when running tests
- comment - (default= ``'#'``) - expression for indicating embedded comments in the test
string; pass None to disable comment filtering
- fullDump - (default= ``True``) - dump results as list followed by results names in nested outline;
if False, only dump nested list
- printResults - (default= ``True``) prints test output to stdout
- failureTests - (default= ``False``) indicates if these tests are expected to fail parsing
- postParse - (default= ``None``) optional callback for successful parse results; called as
`fn(test_string, parse_results)` and returns a string to be added to the test output
- file - (default=``None``) optional file-like object to which test output will be written;
if None, will default to ``sys.stdout``
Returns: a (success, results) tuple, where success indicates that all tests succeeded
(or failed if ``failureTests`` is True), and the results contain a list of lines of each
test's output
Example::
number_expr = pyparsing_common.number.copy()
result = number_expr.runTests('''
# unsigned integer
100
# negative integer
-100
# float with scientific notation
6.02e23
# integer with scientific notation
1e-12
''')
print("Success" if result[0] else "Failed!")
result = number_expr.runTests('''
# stray character
100Z
# missing leading digit before '.'
-.100
# too many '.'
3.14.159
''', failureTests=True)
print("Success" if result[0] else "Failed!")
prints::
# unsigned integer
100
[100]
# negative integer
-100
[-100]
# float with scientific notation
6.02e23
[6.02e+23]
# integer with scientific notation
1e-12
[1e-12]
Success
# stray character
100Z
^
FAIL: Expected end of text (at char 3), (line:1, col:4)
# missing leading digit before '.'
-.100
^
FAIL: Expected {real number with scientific notation | real number | signed integer} (at char 0), (line:1, col:1)
# too many '.'
3.14.159
^
FAIL: Expected end of text (at char 4), (line:1, col:5)
Success
Each test string must be on a single line. If you want to test a string that spans multiple
lines, create a test like this::
expr.runTest(r"this is a test\\n of strings that spans \\n 3 lines")
(Note that this is a raw string literal, you must include the leading 'r'.)
"""
if isinstance(tests, basestring):
tests = list(map(str.strip, tests.rstrip().splitlines()))
if isinstance(comment, basestring):
comment = Literal(comment)
if file is None:
file = sys.stdout
print_ = file.write
allResults = []
comments = []
success = True
NL = Literal(r'\n').addParseAction(replaceWith('\n')).ignore(quotedString)
BOM = u'\ufeff'
for t in tests:
if comment is not None and comment.matches(t, False) or comments and not t:
comments.append(t)
continue
if not t:
continue
out = ['\n' + '\n'.join(comments) if comments else '', t]
comments = []
try:
# convert newline marks to actual newlines, and strip leading BOM if present
t = NL.transformString(t.lstrip(BOM))
result = self.parseString(t, parseAll=parseAll)
except ParseBaseException as pe:
fatal = "(FATAL)" if isinstance(pe, ParseFatalException) else ""
if '\n' in t:
out.append(line(pe.loc, t))
out.append(' ' * (col(pe.loc, t) - 1) + '^' + fatal)
else:
out.append(' ' * pe.loc + '^' + fatal)
out.append("FAIL: " + str(pe))
success = success and failureTests
result = pe
except Exception as exc:
out.append("FAIL-EXCEPTION: " + str(exc))
success = success and failureTests
result = exc
else:
success = success and not failureTests
if postParse is not None:
try:
pp_value = postParse(t, result)
if pp_value is not None:
if isinstance(pp_value, ParseResults):
out.append(pp_value.dump())
else:
out.append(str(pp_value))
else:
out.append(result.dump())
except Exception as e:
out.append(result.dump(full=fullDump))
out.append("{0} failed: {1}: {2}".format(postParse.__name__, type(e).__name__, e))
else:
out.append(result.dump(full=fullDump))
if printResults:
if fullDump:
out.append('')
print_('\n'.join(out))
allResults.append((t, result))
return success, allResults
class _PendingSkip(ParserElement):
# internal placeholder class to hold a place were '...' is added to a parser element,
# once another ParserElement is added, this placeholder will be replaced with a SkipTo
def __init__(self, expr, must_skip=False):
super(_PendingSkip, self).__init__()
self.strRepr = str(expr + Empty()).replace('Empty', '...')
self.name = self.strRepr
self.anchor = expr
self.must_skip = must_skip
def __add__(self, other):
skipper = SkipTo(other).setName("...")("_skipped*")
if self.must_skip:
def must_skip(t):
if not t._skipped or t._skipped.asList() == ['']:
del t[0]
t.pop("_skipped", None)
def show_skip(t):
if t._skipped.asList()[-1:] == ['']:
skipped = t.pop('_skipped')
t['_skipped'] = 'missing <' + repr(self.anchor) + '>'
return (self.anchor + skipper().addParseAction(must_skip)
| skipper().addParseAction(show_skip)) + other
return self.anchor + skipper + other
def __repr__(self):
return self.strRepr
def parseImpl(self, *args):
raise Exception("use of `...` expression without following SkipTo target expression")
class Token(ParserElement):
"""Abstract :class:`ParserElement` subclass, for defining atomic
matching patterns.
"""
def __init__(self):
super(Token, self).__init__(savelist=False)
class Empty(Token):
"""An empty token, will always match.
"""
def __init__(self):
super(Empty, self).__init__()
self.name = "Empty"
self.mayReturnEmpty = True
self.mayIndexError = False
class NoMatch(Token):
"""A token that will never match.
"""
def __init__(self):
super(NoMatch, self).__init__()
self.name = "NoMatch"
self.mayReturnEmpty = True
self.mayIndexError = False
self.errmsg = "Unmatchable token"
def parseImpl(self, instring, loc, doActions=True):
raise ParseException(instring, loc, self.errmsg, self)
class Literal(Token):
"""Token to exactly match a specified string.
Example::
Literal('blah').parseString('blah') # -> ['blah']
Literal('blah').parseString('blahfooblah') # -> ['blah']
Literal('blah').parseString('bla') # -> Exception: Expected "blah"
For case-insensitive matching, use :class:`CaselessLiteral`.
For keyword matching (force word break before and after the matched string),
use :class:`Keyword` or :class:`CaselessKeyword`.
"""
def __init__(self, matchString):
super(Literal, self).__init__()
self.match = matchString
self.matchLen = len(matchString)
try:
self.firstMatchChar = matchString[0]
except IndexError:
warnings.warn("null string passed to Literal; use Empty() instead",
SyntaxWarning, stacklevel=2)
self.__class__ = Empty
self.name = '"%s"' % _ustr(self.match)
self.errmsg = "Expected " + self.name
self.mayReturnEmpty = False
self.mayIndexError = False
# Performance tuning: modify __class__ to select
# a parseImpl optimized for single-character check
if self.matchLen == 1 and type(self) is Literal:
self.__class__ = _SingleCharLiteral
def parseImpl(self, instring, loc, doActions=True):
if instring[loc] == self.firstMatchChar and instring.startswith(self.match, loc):
return loc + self.matchLen, self.match
raise ParseException(instring, loc, self.errmsg, self)
class _SingleCharLiteral(Literal):
def parseImpl(self, instring, loc, doActions=True):
if instring[loc] == self.firstMatchChar:
return loc + 1, self.match
raise ParseException(instring, loc, self.errmsg, self)
_L = Literal
ParserElement._literalStringClass = Literal
class Keyword(Token):
"""Token to exactly match a specified string as a keyword, that is,
it must be immediately followed by a non-keyword character. Compare
with :class:`Literal`:
- ``Literal("if")`` will match the leading ``'if'`` in
``'ifAndOnlyIf'``.
- ``Keyword("if")`` will not; it will only match the leading
``'if'`` in ``'if x=1'``, or ``'if(y==2)'``
Accepts two optional constructor arguments in addition to the
keyword string:
- ``identChars`` is a string of characters that would be valid
identifier characters, defaulting to all alphanumerics + "_" and
"$"
- ``caseless`` allows case-insensitive matching, default is ``False``.
Example::
Keyword("start").parseString("start") # -> ['start']
Keyword("start").parseString("starting") # -> Exception
For case-insensitive matching, use :class:`CaselessKeyword`.
"""
DEFAULT_KEYWORD_CHARS = alphanums + "_$"
def __init__(self, matchString, identChars=None, caseless=False):
super(Keyword, self).__init__()
if identChars is None:
identChars = Keyword.DEFAULT_KEYWORD_CHARS
self.match = matchString
self.matchLen = len(matchString)
try:
self.firstMatchChar = matchString[0]
except IndexError:
warnings.warn("null string passed to Keyword; use Empty() instead",
SyntaxWarning, stacklevel=2)
self.name = '"%s"' % self.match
self.errmsg = "Expected " + self.name
self.mayReturnEmpty = False
self.mayIndexError = False
self.caseless = caseless
if caseless:
self.caselessmatch = matchString.upper()
identChars = identChars.upper()
self.identChars = set(identChars)
def parseImpl(self, instring, loc, doActions=True):
if self.caseless:
if ((instring[loc:loc + self.matchLen].upper() == self.caselessmatch)
and (loc >= len(instring) - self.matchLen
or instring[loc + self.matchLen].upper() not in self.identChars)
and (loc == 0
or instring[loc - 1].upper() not in self.identChars)):
return loc + self.matchLen, self.match
else:
if instring[loc] == self.firstMatchChar:
if ((self.matchLen == 1 or instring.startswith(self.match, loc))
and (loc >= len(instring) - self.matchLen
or instring[loc + self.matchLen] not in self.identChars)
and (loc == 0 or instring[loc - 1] not in self.identChars)):
return loc + self.matchLen, self.match
raise ParseException(instring, loc, self.errmsg, self)
def copy(self):
c = super(Keyword, self).copy()
c.identChars = Keyword.DEFAULT_KEYWORD_CHARS
return c
@staticmethod
def setDefaultKeywordChars(chars):
"""Overrides the default Keyword chars
"""
Keyword.DEFAULT_KEYWORD_CHARS = chars
class CaselessLiteral(Literal):
"""Token to match a specified string, ignoring case of letters.
Note: the matched results will always be in the case of the given
match string, NOT the case of the input text.
Example::
OneOrMore(CaselessLiteral("CMD")).parseString("cmd CMD Cmd10") # -> ['CMD', 'CMD', 'CMD']
(Contrast with example for :class:`CaselessKeyword`.)
"""
def __init__(self, matchString):
super(CaselessLiteral, self).__init__(matchString.upper())
# Preserve the defining literal.
self.returnString = matchString
self.name = "'%s'" % self.returnString
self.errmsg = "Expected " + self.name
def parseImpl(self, instring, loc, doActions=True):
if instring[loc:loc + self.matchLen].upper() == self.match:
return loc + self.matchLen, self.returnString
raise ParseException(instring, loc, self.errmsg, self)
class CaselessKeyword(Keyword):
"""
Caseless version of :class:`Keyword`.
Example::
OneOrMore(CaselessKeyword("CMD")).parseString("cmd CMD Cmd10") # -> ['CMD', 'CMD']
(Contrast with example for :class:`CaselessLiteral`.)
"""
def __init__(self, matchString, identChars=None):
super(CaselessKeyword, self).__init__(matchString, identChars, caseless=True)
class CloseMatch(Token):
"""A variation on :class:`Literal` which matches "close" matches,
that is, strings with at most 'n' mismatching characters.
:class:`CloseMatch` takes parameters:
- ``match_string`` - string to be matched
- ``maxMismatches`` - (``default=1``) maximum number of
mismatches allowed to count as a match
The results from a successful parse will contain the matched text
from the input string and the following named results:
- ``mismatches`` - a list of the positions within the
match_string where mismatches were found
- ``original`` - the original match_string used to compare
against the input string
If ``mismatches`` is an empty list, then the match was an exact
match.
Example::
patt = CloseMatch("ATCATCGAATGGA")
patt.parseString("ATCATCGAAXGGA") # -> (['ATCATCGAAXGGA'], {'mismatches': [[9]], 'original': ['ATCATCGAATGGA']})
patt.parseString("ATCAXCGAAXGGA") # -> Exception: Expected 'ATCATCGAATGGA' (with up to 1 mismatches) (at char 0), (line:1, col:1)
# exact match
patt.parseString("ATCATCGAATGGA") # -> (['ATCATCGAATGGA'], {'mismatches': [[]], 'original': ['ATCATCGAATGGA']})
# close match allowing up to 2 mismatches
patt = CloseMatch("ATCATCGAATGGA", maxMismatches=2)
patt.parseString("ATCAXCGAAXGGA") # -> (['ATCAXCGAAXGGA'], {'mismatches': [[4, 9]], 'original': ['ATCATCGAATGGA']})
"""
def __init__(self, match_string, maxMismatches=1):
super(CloseMatch, self).__init__()
self.name = match_string
self.match_string = match_string
self.maxMismatches = maxMismatches
self.errmsg = "Expected %r (with up to %d mismatches)" % (self.match_string, self.maxMismatches)
self.mayIndexError = False
self.mayReturnEmpty = False
def parseImpl(self, instring, loc, doActions=True):
start = loc
instrlen = len(instring)
maxloc = start + len(self.match_string)
if maxloc <= instrlen:
match_string = self.match_string
match_stringloc = 0
mismatches = []
maxMismatches = self.maxMismatches
for match_stringloc, s_m in enumerate(zip(instring[loc:maxloc], match_string)):
src, mat = s_m
if src != mat:
mismatches.append(match_stringloc)
if len(mismatches) > maxMismatches:
break
else:
loc = match_stringloc + 1
results = ParseResults([instring[start:loc]])
results['original'] = match_string
results['mismatches'] = mismatches
return loc, results
raise ParseException(instring, loc, self.errmsg, self)
class Word(Token):
"""Token for matching words composed of allowed character sets.
Defined with string containing all allowed initial characters, an
optional string containing allowed body characters (if omitted,
defaults to the initial character set), and an optional minimum,
maximum, and/or exact length. The default value for ``min`` is
1 (a minimum value < 1 is not valid); the default values for
``max`` and ``exact`` are 0, meaning no maximum or exact
length restriction. An optional ``excludeChars`` parameter can
list characters that might be found in the input ``bodyChars``
string; useful to define a word of all printables except for one or
two characters, for instance.
:class:`srange` is useful for defining custom character set strings
for defining ``Word`` expressions, using range notation from
regular expression character sets.
A common mistake is to use :class:`Word` to match a specific literal
string, as in ``Word("Address")``. Remember that :class:`Word`
uses the string argument to define *sets* of matchable characters.
This expression would match "Add", "AAA", "dAred", or any other word
made up of the characters 'A', 'd', 'r', 'e', and 's'. To match an
exact literal string, use :class:`Literal` or :class:`Keyword`.
pyparsing includes helper strings for building Words:
- :class:`alphas`
- :class:`nums`
- :class:`alphanums`
- :class:`hexnums`
- :class:`alphas8bit` (alphabetic characters in ASCII range 128-255
- accented, tilded, umlauted, etc.)
- :class:`punc8bit` (non-alphabetic characters in ASCII range
128-255 - currency, symbols, superscripts, diacriticals, etc.)
- :class:`printables` (any non-whitespace character)
Example::
# a word composed of digits
integer = Word(nums) # equivalent to Word("0123456789") or Word(srange("0-9"))
# a word with a leading capital, and zero or more lowercase
capital_word = Word(alphas.upper(), alphas.lower())
# hostnames are alphanumeric, with leading alpha, and '-'
hostname = Word(alphas, alphanums + '-')
# roman numeral (not a strict parser, accepts invalid mix of characters)
roman = Word("IVXLCDM")
# any string of non-whitespace characters, except for ','
csv_value = Word(printables, excludeChars=",")
"""
def __init__(self, initChars, bodyChars=None, min=1, max=0, exact=0, asKeyword=False, excludeChars=None):
super(Word, self).__init__()
if excludeChars:
excludeChars = set(excludeChars)
initChars = ''.join(c for c in initChars if c not in excludeChars)
if bodyChars:
bodyChars = ''.join(c for c in bodyChars if c not in excludeChars)
self.initCharsOrig = initChars
self.initChars = set(initChars)
if bodyChars:
self.bodyCharsOrig = bodyChars
self.bodyChars = set(bodyChars)
else:
self.bodyCharsOrig = initChars
self.bodyChars = set(initChars)
self.maxSpecified = max > 0
if min < 1:
raise ValueError("cannot specify a minimum length < 1; use Optional(Word()) if zero-length word is permitted")
self.minLen = min
if max > 0:
self.maxLen = max
else:
self.maxLen = _MAX_INT
if exact > 0:
self.maxLen = exact
self.minLen = exact
self.name = _ustr(self)
self.errmsg = "Expected " + self.name
self.mayIndexError = False
self.asKeyword = asKeyword
if ' ' not in self.initCharsOrig + self.bodyCharsOrig and (min == 1 and max == 0 and exact == 0):
if self.bodyCharsOrig == self.initCharsOrig:
self.reString = "[%s]+" % _escapeRegexRangeChars(self.initCharsOrig)
elif len(self.initCharsOrig) == 1:
self.reString = "%s[%s]*" % (re.escape(self.initCharsOrig),
_escapeRegexRangeChars(self.bodyCharsOrig),)
else:
self.reString = "[%s][%s]*" % (_escapeRegexRangeChars(self.initCharsOrig),
_escapeRegexRangeChars(self.bodyCharsOrig),)
if self.asKeyword:
self.reString = r"\b" + self.reString + r"\b"
try:
self.re = re.compile(self.reString)
except Exception:
self.re = None
else:
self.re_match = self.re.match
self.__class__ = _WordRegex
def parseImpl(self, instring, loc, doActions=True):
if instring[loc] not in self.initChars:
raise ParseException(instring, loc, self.errmsg, self)
start = loc
loc += 1
instrlen = len(instring)
bodychars = self.bodyChars
maxloc = start + self.maxLen
maxloc = min(maxloc, instrlen)
while loc < maxloc and instring[loc] in bodychars:
loc += 1
throwException = False
if loc - start < self.minLen:
throwException = True
elif self.maxSpecified and loc < instrlen and instring[loc] in bodychars:
throwException = True
elif self.asKeyword:
if (start > 0 and instring[start - 1] in bodychars
or loc < instrlen and instring[loc] in bodychars):
throwException = True
if throwException:
raise ParseException(instring, loc, self.errmsg, self)
return loc, instring[start:loc]
def __str__(self):
try:
return super(Word, self).__str__()
except Exception:
pass
if self.strRepr is None:
def charsAsStr(s):
if len(s) > 4:
return s[:4] + "..."
else:
return s
if self.initCharsOrig != self.bodyCharsOrig:
self.strRepr = "W:(%s, %s)" % (charsAsStr(self.initCharsOrig), charsAsStr(self.bodyCharsOrig))
else:
self.strRepr = "W:(%s)" % charsAsStr(self.initCharsOrig)
return self.strRepr
class _WordRegex(Word):
def parseImpl(self, instring, loc, doActions=True):
result = self.re_match(instring, loc)
if not result:
raise ParseException(instring, loc, self.errmsg, self)
loc = result.end()
return loc, result.group()
class Char(_WordRegex):
"""A short-cut class for defining ``Word(characters, exact=1)``,
when defining a match of any single character in a string of
characters.
"""
def __init__(self, charset, asKeyword=False, excludeChars=None):
super(Char, self).__init__(charset, exact=1, asKeyword=asKeyword, excludeChars=excludeChars)
self.reString = "[%s]" % _escapeRegexRangeChars(''.join(self.initChars))
if asKeyword:
self.reString = r"\b%s\b" % self.reString
self.re = re.compile(self.reString)
self.re_match = self.re.match
class Regex(Token):
r"""Token for matching strings that match a given regular
expression. Defined with string specifying the regular expression in
a form recognized by the stdlib Python `re module <https://docs.python.org/3/library/re.html>`_.
If the given regex contains named groups (defined using ``(?P<name>...)``),
these will be preserved as named parse results.
If instead of the Python stdlib re module you wish to use a different RE module
(such as the `regex` module), you can replace it by either building your
Regex object with a compiled RE that was compiled using regex:
Example::
realnum = Regex(r"[+-]?\d+\.\d*")
date = Regex(r'(?P<year>\d{4})-(?P<month>\d\d?)-(?P<day>\d\d?)')
# ref: https://stackoverflow.com/questions/267399/how-do-you-match-only-valid-roman-numerals-with-a-regular-expression
roman = Regex(r"M{0,4}(CM|CD|D?{0,3})(XC|XL|L?X{0,3})(IX|IV|V?I{0,3})")
# use regex module instead of stdlib re module to construct a Regex using
# a compiled regular expression
import regex
parser = pp.Regex(regex.compile(r'[0-9]'))
"""
def __init__(self, pattern, flags=0, asGroupList=False, asMatch=False):
"""The parameters ``pattern`` and ``flags`` are passed
to the ``re.compile()`` function as-is. See the Python
`re module <https://docs.python.org/3/library/re.html>`_ module for an
explanation of the acceptable patterns and flags.
"""
super(Regex, self).__init__()
if isinstance(pattern, basestring):
if not pattern:
warnings.warn("null string passed to Regex; use Empty() instead",
SyntaxWarning, stacklevel=2)
self.pattern = pattern
self.flags = flags
try:
self.re = re.compile(self.pattern, self.flags)
self.reString = self.pattern
except sre_constants.error:
warnings.warn("invalid pattern (%s) passed to Regex" % pattern,
SyntaxWarning, stacklevel=2)
raise
elif hasattr(pattern, 'pattern') and hasattr(pattern, 'match'):
self.re = pattern
self.pattern = self.reString = pattern.pattern
self.flags = flags
else:
raise TypeError("Regex may only be constructed with a string or a compiled RE object")
self.re_match = self.re.match
self.name = _ustr(self)
self.errmsg = "Expected " + self.name
self.mayIndexError = False
self.mayReturnEmpty = self.re_match("") is not None
self.asGroupList = asGroupList
self.asMatch = asMatch
if self.asGroupList:
self.parseImpl = self.parseImplAsGroupList
if self.asMatch:
self.parseImpl = self.parseImplAsMatch
def parseImpl(self, instring, loc, doActions=True):
result = self.re_match(instring, loc)
if not result:
raise ParseException(instring, loc, self.errmsg, self)
loc = result.end()
ret = ParseResults(result.group())
d = result.groupdict()
if d:
for k, v in d.items():
ret[k] = v
return loc, ret
def parseImplAsGroupList(self, instring, loc, doActions=True):
result = self.re_match(instring, loc)
if not result:
raise ParseException(instring, loc, self.errmsg, self)
loc = result.end()
ret = result.groups()
return loc, ret
def parseImplAsMatch(self, instring, loc, doActions=True):
result = self.re_match(instring, loc)
if not result:
raise ParseException(instring, loc, self.errmsg, self)
loc = result.end()
ret = result
return loc, ret
def __str__(self):
try:
return super(Regex, self).__str__()
except Exception:
pass
if self.strRepr is None:
self.strRepr = "Re:(%s)" % repr(self.pattern)
return self.strRepr
def sub(self, repl):
r"""
Return Regex with an attached parse action to transform the parsed
result as if called using `re.sub(expr, repl, string) <https://docs.python.org/3/library/re.html#re.sub>`_.
Example::
make_html = Regex(r"(\w+):(.*?):").sub(r"<\1>\2</\1>")
print(make_html.transformString("h1:main title:"))
# prints "<h1>main title</h1>"
"""
if self.asGroupList:
warnings.warn("cannot use sub() with Regex(asGroupList=True)",
SyntaxWarning, stacklevel=2)
raise SyntaxError()
if self.asMatch and callable(repl):
warnings.warn("cannot use sub() with a callable with Regex(asMatch=True)",
SyntaxWarning, stacklevel=2)
raise SyntaxError()
if self.asMatch:
def pa(tokens):
return tokens[0].expand(repl)
else:
def pa(tokens):
return self.re.sub(repl, tokens[0])
return self.addParseAction(pa)
class QuotedString(Token):
r"""
Token for matching strings that are delimited by quoting characters.
Defined with the following parameters:
- quoteChar - string of one or more characters defining the
quote delimiting string
- escChar - character to escape quotes, typically backslash
(default= ``None``)
- escQuote - special quote sequence to escape an embedded quote
string (such as SQL's ``""`` to escape an embedded ``"``)
(default= ``None``)
- multiline - boolean indicating whether quotes can span
multiple lines (default= ``False``)
- unquoteResults - boolean indicating whether the matched text
should be unquoted (default= ``True``)
- endQuoteChar - string of one or more characters defining the
end of the quote delimited string (default= ``None`` => same as
quoteChar)
- convertWhitespaceEscapes - convert escaped whitespace
(``'\t'``, ``'\n'``, etc.) to actual whitespace
(default= ``True``)
Example::
qs = QuotedString('"')
print(qs.searchString('lsjdf "This is the quote" sldjf'))
complex_qs = QuotedString('{{', endQuoteChar='}}')
print(complex_qs.searchString('lsjdf {{This is the "quote"}} sldjf'))
sql_qs = QuotedString('"', escQuote='""')
print(sql_qs.searchString('lsjdf "This is the quote with ""embedded"" quotes" sldjf'))
prints::
[['This is the quote']]
[['This is the "quote"']]
[['This is the quote with "embedded" quotes']]
"""
def __init__(self, quoteChar, escChar=None, escQuote=None, multiline=False,
unquoteResults=True, endQuoteChar=None, convertWhitespaceEscapes=True):
super(QuotedString, self).__init__()
# remove white space from quote chars - wont work anyway
quoteChar = quoteChar.strip()
if not quoteChar:
warnings.warn("quoteChar cannot be the empty string", SyntaxWarning, stacklevel=2)
raise SyntaxError()
if endQuoteChar is None:
endQuoteChar = quoteChar
else:
endQuoteChar = endQuoteChar.strip()
if not endQuoteChar:
warnings.warn("endQuoteChar cannot be the empty string", SyntaxWarning, stacklevel=2)
raise SyntaxError()
self.quoteChar = quoteChar
self.quoteCharLen = len(quoteChar)
self.firstQuoteChar = quoteChar[0]
self.endQuoteChar = endQuoteChar
self.endQuoteCharLen = len(endQuoteChar)
self.escChar = escChar
self.escQuote = escQuote
self.unquoteResults = unquoteResults
self.convertWhitespaceEscapes = convertWhitespaceEscapes
if multiline:
self.flags = re.MULTILINE | re.DOTALL
self.pattern = r'%s(?:[^%s%s]' % (re.escape(self.quoteChar),
_escapeRegexRangeChars(self.endQuoteChar[0]),
(escChar is not None and _escapeRegexRangeChars(escChar) or ''))
else:
self.flags = 0
self.pattern = r'%s(?:[^%s\n\r%s]' % (re.escape(self.quoteChar),
_escapeRegexRangeChars(self.endQuoteChar[0]),
(escChar is not None and _escapeRegexRangeChars(escChar) or ''))
if len(self.endQuoteChar) > 1:
self.pattern += (
'|(?:' + ')|(?:'.join("%s[^%s]" % (re.escape(self.endQuoteChar[:i]),
_escapeRegexRangeChars(self.endQuoteChar[i]))
for i in range(len(self.endQuoteChar) - 1, 0, -1)) + ')')
if escQuote:
self.pattern += (r'|(?:%s)' % re.escape(escQuote))
if escChar:
self.pattern += (r'|(?:%s.)' % re.escape(escChar))
self.escCharReplacePattern = re.escape(self.escChar) + "(.)"
self.pattern += (r')*%s' % re.escape(self.endQuoteChar))
try:
self.re = re.compile(self.pattern, self.flags)
self.reString = self.pattern
self.re_match = self.re.match
except sre_constants.error:
warnings.warn("invalid pattern (%s) passed to Regex" % self.pattern,
SyntaxWarning, stacklevel=2)
raise
self.name = _ustr(self)
self.errmsg = "Expected " + self.name
self.mayIndexError = False
self.mayReturnEmpty = True
def parseImpl(self, instring, loc, doActions=True):
result = instring[loc] == self.firstQuoteChar and self.re_match(instring, loc) or None
if not result:
raise ParseException(instring, loc, self.errmsg, self)
loc = result.end()
ret = result.group()
if self.unquoteResults:
# strip off quotes
ret = ret[self.quoteCharLen: -self.endQuoteCharLen]
if isinstance(ret, basestring):
# replace escaped whitespace
if '\\' in ret and self.convertWhitespaceEscapes:
ws_map = {
r'\t': '\t',
r'\n': '\n',
r'\f': '\f',
r'\r': '\r',
}
for wslit, wschar in ws_map.items():
ret = ret.replace(wslit, wschar)
# replace escaped characters
if self.escChar:
ret = re.sub(self.escCharReplacePattern, r"\g<1>", ret)
# replace escaped quotes
if self.escQuote:
ret = ret.replace(self.escQuote, self.endQuoteChar)
return loc, ret
def __str__(self):
try:
return super(QuotedString, self).__str__()
except Exception:
pass
if self.strRepr is None:
self.strRepr = "quoted string, starting with %s ending with %s" % (self.quoteChar, self.endQuoteChar)
return self.strRepr
class CharsNotIn(Token):
"""Token for matching words composed of characters *not* in a given
set (will include whitespace in matched characters if not listed in
the provided exclusion set - see example). Defined with string
containing all disallowed characters, and an optional minimum,
maximum, and/or exact length. The default value for ``min`` is
1 (a minimum value < 1 is not valid); the default values for
``max`` and ``exact`` are 0, meaning no maximum or exact
length restriction.
Example::
# define a comma-separated-value as anything that is not a ','
csv_value = CharsNotIn(',')
print(delimitedList(csv_value).parseString("dkls,lsdkjf,s12 34,@!#,213"))
prints::
['dkls', 'lsdkjf', 's12 34', '@!#', '213']
"""
def __init__(self, notChars, min=1, max=0, exact=0):
super(CharsNotIn, self).__init__()
self.skipWhitespace = False
self.notChars = notChars
if min < 1:
raise ValueError("cannot specify a minimum length < 1; use "
"Optional(CharsNotIn()) if zero-length char group is permitted")
self.minLen = min
if max > 0:
self.maxLen = max
else:
self.maxLen = _MAX_INT
if exact > 0:
self.maxLen = exact
self.minLen = exact
self.name = _ustr(self)
self.errmsg = "Expected " + self.name
self.mayReturnEmpty = (self.minLen == 0)
self.mayIndexError = False
def parseImpl(self, instring, loc, doActions=True):
if instring[loc] in self.notChars:
raise ParseException(instring, loc, self.errmsg, self)
start = loc
loc += 1
notchars = self.notChars
maxlen = min(start + self.maxLen, len(instring))
while loc < maxlen and instring[loc] not in notchars:
loc += 1
if loc - start < self.minLen:
raise ParseException(instring, loc, self.errmsg, self)
return loc, instring[start:loc]
def __str__(self):
try:
return super(CharsNotIn, self).__str__()
except Exception:
pass
if self.strRepr is None:
if len(self.notChars) > 4:
self.strRepr = "!W:(%s...)" % self.notChars[:4]
else:
self.strRepr = "!W:(%s)" % self.notChars
return self.strRepr
class White(Token):
"""Special matching class for matching whitespace. Normally,
whitespace is ignored by pyparsing grammars. This class is included
when some whitespace structures are significant. Define with
a string containing the whitespace characters to be matched; default
is ``" \\t\\r\\n"``. Also takes optional ``min``,
``max``, and ``exact`` arguments, as defined for the
:class:`Word` class.
"""
whiteStrs = {
' ' : '<SP>',
'\t': '<TAB>',
'\n': '<LF>',
'\r': '<CR>',
'\f': '<FF>',
u'\u00A0': '<NBSP>',
u'\u1680': '<OGHAM_SPACE_MARK>',
u'\u180E': '<MONGOLIAN_VOWEL_SEPARATOR>',
u'\u2000': '<EN_QUAD>',
u'\u2001': '<EM_QUAD>',
u'\u2002': '<EN_SPACE>',
u'\u2003': '<EM_SPACE>',
u'\u2004': '<THREE-PER-EM_SPACE>',
u'\u2005': '<FOUR-PER-EM_SPACE>',
u'\u2006': '<SIX-PER-EM_SPACE>',
u'\u2007': '<FIGURE_SPACE>',
u'\u2008': '<PUNCTUATION_SPACE>',
u'\u2009': '<THIN_SPACE>',
u'\u200A': '<HAIR_SPACE>',
u'\u200B': '<ZERO_WIDTH_SPACE>',
u'\u202F': '<NNBSP>',
u'\u205F': '<MMSP>',
u'\u3000': '<IDEOGRAPHIC_SPACE>',
}
def __init__(self, ws=" \t\r\n", min=1, max=0, exact=0):
super(White, self).__init__()
self.matchWhite = ws
self.setWhitespaceChars("".join(c for c in self.whiteChars if c not in self.matchWhite))
# ~ self.leaveWhitespace()
self.name = ("".join(White.whiteStrs[c] for c in self.matchWhite))
self.mayReturnEmpty = True
self.errmsg = "Expected " + self.name
self.minLen = min
if max > 0:
self.maxLen = max
else:
self.maxLen = _MAX_INT
if exact > 0:
self.maxLen = exact
self.minLen = exact
def parseImpl(self, instring, loc, doActions=True):
if instring[loc] not in self.matchWhite:
raise ParseException(instring, loc, self.errmsg, self)
start = loc
loc += 1
maxloc = start + self.maxLen
maxloc = min(maxloc, len(instring))
while loc < maxloc and instring[loc] in self.matchWhite:
loc += 1
if loc - start < self.minLen:
raise ParseException(instring, loc, self.errmsg, self)
return loc, instring[start:loc]
class _PositionToken(Token):
def __init__(self):
super(_PositionToken, self).__init__()
self.name = self.__class__.__name__
self.mayReturnEmpty = True
self.mayIndexError = False
class GoToColumn(_PositionToken):
"""Token to advance to a specific column of input text; useful for
tabular report scraping.
"""
def __init__(self, colno):
super(GoToColumn, self).__init__()
self.col = colno
def preParse(self, instring, loc):
if col(loc, instring) != self.col:
instrlen = len(instring)
if self.ignoreExprs:
loc = self._skipIgnorables(instring, loc)
while loc < instrlen and instring[loc].isspace() and col(loc, instring) != self.col:
loc += 1
return loc
def parseImpl(self, instring, loc, doActions=True):
thiscol = col(loc, instring)
if thiscol > self.col:
raise ParseException(instring, loc, "Text not in expected column", self)
newloc = loc + self.col - thiscol
ret = instring[loc: newloc]
return newloc, ret
class LineStart(_PositionToken):
r"""Matches if current position is at the beginning of a line within
the parse string
Example::
test = '''\
AAA this line
AAA and this line
AAA but not this one
B AAA and definitely not this one
'''
for t in (LineStart() + 'AAA' + restOfLine).searchString(test):
print(t)
prints::
['AAA', ' this line']
['AAA', ' and this line']
"""
def __init__(self):
super(LineStart, self).__init__()
self.errmsg = "Expected start of line"
def parseImpl(self, instring, loc, doActions=True):
if col(loc, instring) == 1:
return loc, []
raise ParseException(instring, loc, self.errmsg, self)
class LineEnd(_PositionToken):
"""Matches if current position is at the end of a line within the
parse string
"""
def __init__(self):
super(LineEnd, self).__init__()
self.setWhitespaceChars(ParserElement.DEFAULT_WHITE_CHARS.replace("\n", ""))
self.errmsg = "Expected end of line"
def parseImpl(self, instring, loc, doActions=True):
if loc < len(instring):
if instring[loc] == "\n":
return loc + 1, "\n"
else:
raise ParseException(instring, loc, self.errmsg, self)
elif loc == len(instring):
return loc + 1, []
else:
raise ParseException(instring, loc, self.errmsg, self)
class StringStart(_PositionToken):
"""Matches if current position is at the beginning of the parse
string
"""
def __init__(self):
super(StringStart, self).__init__()
self.errmsg = "Expected start of text"
def parseImpl(self, instring, loc, doActions=True):
if loc != 0:
# see if entire string up to here is just whitespace and ignoreables
if loc != self.preParse(instring, 0):
raise ParseException(instring, loc, self.errmsg, self)
return loc, []
class StringEnd(_PositionToken):
"""Matches if current position is at the end of the parse string
"""
def __init__(self):
super(StringEnd, self).__init__()
self.errmsg = "Expected end of text"
def parseImpl(self, instring, loc, doActions=True):
if loc < len(instring):
raise ParseException(instring, loc, self.errmsg, self)
elif loc == len(instring):
return loc + 1, []
elif loc > len(instring):
return loc, []
else:
raise ParseException(instring, loc, self.errmsg, self)
class WordStart(_PositionToken):
"""Matches if the current position is at the beginning of a Word,
and is not preceded by any character in a given set of
``wordChars`` (default= ``printables``). To emulate the
``\b`` behavior of regular expressions, use
``WordStart(alphanums)``. ``WordStart`` will also match at
the beginning of the string being parsed, or at the beginning of
a line.
"""
def __init__(self, wordChars=printables):
super(WordStart, self).__init__()
self.wordChars = set(wordChars)
self.errmsg = "Not at the start of a word"
def parseImpl(self, instring, loc, doActions=True):
if loc != 0:
if (instring[loc - 1] in self.wordChars
or instring[loc] not in self.wordChars):
raise ParseException(instring, loc, self.errmsg, self)
return loc, []
class WordEnd(_PositionToken):
"""Matches if the current position is at the end of a Word, and is
not followed by any character in a given set of ``wordChars``
(default= ``printables``). To emulate the ``\b`` behavior of
regular expressions, use ``WordEnd(alphanums)``. ``WordEnd``
will also match at the end of the string being parsed, or at the end
of a line.
"""
def __init__(self, wordChars=printables):
super(WordEnd, self).__init__()
self.wordChars = set(wordChars)
self.skipWhitespace = False
self.errmsg = "Not at the end of a word"
def parseImpl(self, instring, loc, doActions=True):
instrlen = len(instring)
if instrlen > 0 and loc < instrlen:
if (instring[loc] in self.wordChars or
instring[loc - 1] not in self.wordChars):
raise ParseException(instring, loc, self.errmsg, self)
return loc, []
class ParseExpression(ParserElement):
"""Abstract subclass of ParserElement, for combining and
post-processing parsed tokens.
"""
def __init__(self, exprs, savelist=False):
super(ParseExpression, self).__init__(savelist)
if isinstance(exprs, _generatorType):
exprs = list(exprs)
if isinstance(exprs, basestring):
self.exprs = [self._literalStringClass(exprs)]
elif isinstance(exprs, ParserElement):
self.exprs = [exprs]
elif isinstance(exprs, Iterable):
exprs = list(exprs)
# if sequence of strings provided, wrap with Literal
if any(isinstance(expr, basestring) for expr in exprs):
exprs = (self._literalStringClass(e) if isinstance(e, basestring) else e for e in exprs)
self.exprs = list(exprs)
else:
try:
self.exprs = list(exprs)
except TypeError:
self.exprs = [exprs]
self.callPreparse = False
def append(self, other):
self.exprs.append(other)
self.strRepr = None
return self
def leaveWhitespace(self):
"""Extends ``leaveWhitespace`` defined in base class, and also invokes ``leaveWhitespace`` on
all contained expressions."""
self.skipWhitespace = False
self.exprs = [e.copy() for e in self.exprs]
for e in self.exprs:
e.leaveWhitespace()
return self
def ignore(self, other):
if isinstance(other, Suppress):
if other not in self.ignoreExprs:
super(ParseExpression, self).ignore(other)
for e in self.exprs:
e.ignore(self.ignoreExprs[-1])
else:
super(ParseExpression, self).ignore(other)
for e in self.exprs:
e.ignore(self.ignoreExprs[-1])
return self
def __str__(self):
try:
return super(ParseExpression, self).__str__()
except Exception:
pass
if self.strRepr is None:
self.strRepr = "%s:(%s)" % (self.__class__.__name__, _ustr(self.exprs))
return self.strRepr
def streamline(self):
super(ParseExpression, self).streamline()
for e in self.exprs:
e.streamline()
# collapse nested And's of the form And(And(And(a, b), c), d) to And(a, b, c, d)
# but only if there are no parse actions or resultsNames on the nested And's
# (likewise for Or's and MatchFirst's)
if len(self.exprs) == 2:
other = self.exprs[0]
if (isinstance(other, self.__class__)
and not other.parseAction
and other.resultsName is None
and not other.debug):
self.exprs = other.exprs[:] + [self.exprs[1]]
self.strRepr = None
self.mayReturnEmpty |= other.mayReturnEmpty
self.mayIndexError |= other.mayIndexError
other = self.exprs[-1]
if (isinstance(other, self.__class__)
and not other.parseAction
and other.resultsName is None
and not other.debug):
self.exprs = self.exprs[:-1] + other.exprs[:]
self.strRepr = None
self.mayReturnEmpty |= other.mayReturnEmpty
self.mayIndexError |= other.mayIndexError
self.errmsg = "Expected " + _ustr(self)
return self
def validate(self, validateTrace=None):
tmp = (validateTrace if validateTrace is not None else [])[:] + [self]
for e in self.exprs:
e.validate(tmp)
self.checkRecursion([])
def copy(self):
ret = super(ParseExpression, self).copy()
ret.exprs = [e.copy() for e in self.exprs]
return ret
def _setResultsName(self, name, listAllMatches=False):
if __diag__.warn_ungrouped_named_tokens_in_collection:
for e in self.exprs:
if isinstance(e, ParserElement) and e.resultsName:
warnings.warn("{0}: setting results name {1!r} on {2} expression "
"collides with {3!r} on contained expression".format("warn_ungrouped_named_tokens_in_collection",
name,
type(self).__name__,
e.resultsName),
stacklevel=3)
return super(ParseExpression, self)._setResultsName(name, listAllMatches)
class And(ParseExpression):
"""
Requires all given :class:`ParseExpression` s to be found in the given order.
Expressions may be separated by whitespace.
May be constructed using the ``'+'`` operator.
May also be constructed using the ``'-'`` operator, which will
suppress backtracking.
Example::
integer = Word(nums)
name_expr = OneOrMore(Word(alphas))
expr = And([integer("id"), name_expr("name"), integer("age")])
# more easily written as:
expr = integer("id") + name_expr("name") + integer("age")
"""
class _ErrorStop(Empty):
def __init__(self, *args, **kwargs):
super(And._ErrorStop, self).__init__(*args, **kwargs)
self.name = '-'
self.leaveWhitespace()
def __init__(self, exprs, savelist=True):
exprs = list(exprs)
if exprs and Ellipsis in exprs:
tmp = []
for i, expr in enumerate(exprs):
if expr is Ellipsis:
if i < len(exprs) - 1:
skipto_arg = (Empty() + exprs[i + 1]).exprs[-1]
tmp.append(SkipTo(skipto_arg)("_skipped*"))
else:
raise Exception("cannot construct And with sequence ending in ...")
else:
tmp.append(expr)
exprs[:] = tmp
super(And, self).__init__(exprs, savelist)
self.mayReturnEmpty = all(e.mayReturnEmpty for e in self.exprs)
self.setWhitespaceChars(self.exprs[0].whiteChars)
self.skipWhitespace = self.exprs[0].skipWhitespace
self.callPreparse = True
def streamline(self):
# collapse any _PendingSkip's
if self.exprs:
if any(isinstance(e, ParseExpression) and e.exprs and isinstance(e.exprs[-1], _PendingSkip)
for e in self.exprs[:-1]):
for i, e in enumerate(self.exprs[:-1]):
if e is None:
continue
if (isinstance(e, ParseExpression)
and e.exprs and isinstance(e.exprs[-1], _PendingSkip)):
e.exprs[-1] = e.exprs[-1] + self.exprs[i + 1]
self.exprs[i + 1] = None
self.exprs = [e for e in self.exprs if e is not None]
super(And, self).streamline()
self.mayReturnEmpty = all(e.mayReturnEmpty for e in self.exprs)
return self
def parseImpl(self, instring, loc, doActions=True):
# pass False as last arg to _parse for first element, since we already
# pre-parsed the string as part of our And pre-parsing
loc, resultlist = self.exprs[0]._parse(instring, loc, doActions, callPreParse=False)
errorStop = False
for e in self.exprs[1:]:
if isinstance(e, And._ErrorStop):
errorStop = True
continue
if errorStop:
try:
loc, exprtokens = e._parse(instring, loc, doActions)
except ParseSyntaxException:
raise
except ParseBaseException as pe:
pe.__traceback__ = None
raise ParseSyntaxException._from_exception(pe)
except IndexError:
raise ParseSyntaxException(instring, len(instring), self.errmsg, self)
else:
loc, exprtokens = e._parse(instring, loc, doActions)
if exprtokens or exprtokens.haskeys():
resultlist += exprtokens
return loc, resultlist
def __iadd__(self, other):
if isinstance(other, basestring):
other = self._literalStringClass(other)
return self.append(other) # And([self, other])
def checkRecursion(self, parseElementList):
subRecCheckList = parseElementList[:] + [self]
for e in self.exprs:
e.checkRecursion(subRecCheckList)
if not e.mayReturnEmpty:
break
def __str__(self):
if hasattr(self, "name"):
return self.name
if self.strRepr is None:
self.strRepr = "{" + " ".join(_ustr(e) for e in self.exprs) + "}"
return self.strRepr
class Or(ParseExpression):
"""Requires that at least one :class:`ParseExpression` is found. If
two expressions match, the expression that matches the longest
string will be used. May be constructed using the ``'^'``
operator.
Example::
# construct Or using '^' operator
number = Word(nums) ^ Combine(Word(nums) + '.' + Word(nums))
print(number.searchString("123 3.1416 789"))
prints::
[['123'], ['3.1416'], ['789']]
"""
def __init__(self, exprs, savelist=False):
super(Or, self).__init__(exprs, savelist)
if self.exprs:
self.mayReturnEmpty = any(e.mayReturnEmpty for e in self.exprs)
else:
self.mayReturnEmpty = True
def streamline(self):
super(Or, self).streamline()
if __compat__.collect_all_And_tokens:
self.saveAsList = any(e.saveAsList for e in self.exprs)
return self
def parseImpl(self, instring, loc, doActions=True):
maxExcLoc = -1
maxException = None
matches = []
for e in self.exprs:
try:
loc2 = e.tryParse(instring, loc)
except ParseException as err:
err.__traceback__ = None
if err.loc > maxExcLoc:
maxException = err
maxExcLoc = err.loc
except IndexError:
if len(instring) > maxExcLoc:
maxException = ParseException(instring, len(instring), e.errmsg, self)
maxExcLoc = len(instring)
else:
# save match among all matches, to retry longest to shortest
matches.append((loc2, e))
if matches:
# re-evaluate all matches in descending order of length of match, in case attached actions
# might change whether or how much they match of the input.
matches.sort(key=itemgetter(0), reverse=True)
if not doActions:
# no further conditions or parse actions to change the selection of
# alternative, so the first match will be the best match
best_expr = matches[0][1]
return best_expr._parse(instring, loc, doActions)
longest = -1, None
for loc1, expr1 in matches:
if loc1 <= longest[0]:
# already have a longer match than this one will deliver, we are done
return longest
try:
loc2, toks = expr1._parse(instring, loc, doActions)
except ParseException as err:
err.__traceback__ = None
if err.loc > maxExcLoc:
maxException = err
maxExcLoc = err.loc
else:
if loc2 >= loc1:
return loc2, toks
# didn't match as much as before
elif loc2 > longest[0]:
longest = loc2, toks
if longest != (-1, None):
return longest
if maxException is not None:
maxException.msg = self.errmsg
raise maxException
else:
raise ParseException(instring, loc, "no defined alternatives to match", self)
def __ixor__(self, other):
if isinstance(other, basestring):
other = self._literalStringClass(other)
return self.append(other) # Or([self, other])
def __str__(self):
if hasattr(self, "name"):
return self.name
if self.strRepr is None:
self.strRepr = "{" + " ^ ".join(_ustr(e) for e in self.exprs) + "}"
return self.strRepr
def checkRecursion(self, parseElementList):
subRecCheckList = parseElementList[:] + [self]
for e in self.exprs:
e.checkRecursion(subRecCheckList)
def _setResultsName(self, name, listAllMatches=False):
if (not __compat__.collect_all_And_tokens
and __diag__.warn_multiple_tokens_in_named_alternation):
if any(isinstance(e, And) for e in self.exprs):
warnings.warn("{0}: setting results name {1!r} on {2} expression "
"may only return a single token for an And alternative, "
"in future will return the full list of tokens".format(
"warn_multiple_tokens_in_named_alternation", name, type(self).__name__),
stacklevel=3)
return super(Or, self)._setResultsName(name, listAllMatches)
class MatchFirst(ParseExpression):
"""Requires that at least one :class:`ParseExpression` is found. If
two expressions match, the first one listed is the one that will
match. May be constructed using the ``'|'`` operator.
Example::
# construct MatchFirst using '|' operator
# watch the order of expressions to match
number = Word(nums) | Combine(Word(nums) + '.' + Word(nums))
print(number.searchString("123 3.1416 789")) # Fail! -> [['123'], ['3'], ['1416'], ['789']]
# put more selective expression first
number = Combine(Word(nums) + '.' + Word(nums)) | Word(nums)
print(number.searchString("123 3.1416 789")) # Better -> [['123'], ['3.1416'], ['789']]
"""
def __init__(self, exprs, savelist=False):
super(MatchFirst, self).__init__(exprs, savelist)
if self.exprs:
self.mayReturnEmpty = any(e.mayReturnEmpty for e in self.exprs)
else:
self.mayReturnEmpty = True
def streamline(self):
super(MatchFirst, self).streamline()
if __compat__.collect_all_And_tokens:
self.saveAsList = any(e.saveAsList for e in self.exprs)
return self
def parseImpl(self, instring, loc, doActions=True):
maxExcLoc = -1
maxException = None
for e in self.exprs:
try:
ret = e._parse(instring, loc, doActions)
return ret
except ParseException as err:
if err.loc > maxExcLoc:
maxException = err
maxExcLoc = err.loc
except IndexError:
if len(instring) > maxExcLoc:
maxException = ParseException(instring, len(instring), e.errmsg, self)
maxExcLoc = len(instring)
# only got here if no expression matched, raise exception for match that made it the furthest
else:
if maxException is not None:
maxException.msg = self.errmsg
raise maxException
else:
raise ParseException(instring, loc, "no defined alternatives to match", self)
def __ior__(self, other):
if isinstance(other, basestring):
other = self._literalStringClass(other)
return self.append(other) # MatchFirst([self, other])
def __str__(self):
if hasattr(self, "name"):
return self.name
if self.strRepr is None:
self.strRepr = "{" + " | ".join(_ustr(e) for e in self.exprs) + "}"
return self.strRepr
def checkRecursion(self, parseElementList):
subRecCheckList = parseElementList[:] + [self]
for e in self.exprs:
e.checkRecursion(subRecCheckList)
def _setResultsName(self, name, listAllMatches=False):
if (not __compat__.collect_all_And_tokens
and __diag__.warn_multiple_tokens_in_named_alternation):
if any(isinstance(e, And) for e in self.exprs):
warnings.warn("{0}: setting results name {1!r} on {2} expression "
"may only return a single token for an And alternative, "
"in future will return the full list of tokens".format(
"warn_multiple_tokens_in_named_alternation", name, type(self).__name__),
stacklevel=3)
return super(MatchFirst, self)._setResultsName(name, listAllMatches)
class Each(ParseExpression):
"""Requires all given :class:`ParseExpression` s to be found, but in
any order. Expressions may be separated by whitespace.
May be constructed using the ``'&'`` operator.
Example::
color = oneOf("RED ORANGE YELLOW GREEN BLUE PURPLE BLACK WHITE BROWN")
shape_type = oneOf("SQUARE CIRCLE TRIANGLE STAR HEXAGON OCTAGON")
integer = Word(nums)
shape_attr = "shape:" + shape_type("shape")
posn_attr = "posn:" + Group(integer("x") + ',' + integer("y"))("posn")
color_attr = "color:" + color("color")
size_attr = "size:" + integer("size")
# use Each (using operator '&') to accept attributes in any order
# (shape and posn are required, color and size are optional)
shape_spec = shape_attr & posn_attr & Optional(color_attr) & Optional(size_attr)
shape_spec.runTests('''
shape: SQUARE color: BLACK posn: 100, 120
shape: CIRCLE size: 50 color: BLUE posn: 50,80
color:GREEN size:20 shape:TRIANGLE posn:20,40
'''
)
prints::
shape: SQUARE color: BLACK posn: 100, 120
['shape:', 'SQUARE', 'color:', 'BLACK', 'posn:', ['100', ',', '120']]
- color: BLACK
- posn: ['100', ',', '120']
- x: 100
- y: 120
- shape: SQUARE
shape: CIRCLE size: 50 color: BLUE posn: 50,80
['shape:', 'CIRCLE', 'size:', '50', 'color:', 'BLUE', 'posn:', ['50', ',', '80']]
- color: BLUE
- posn: ['50', ',', '80']
- x: 50
- y: 80
- shape: CIRCLE
- size: 50
color: GREEN size: 20 shape: TRIANGLE posn: 20,40
['color:', 'GREEN', 'size:', '20', 'shape:', 'TRIANGLE', 'posn:', ['20', ',', '40']]
- color: GREEN
- posn: ['20', ',', '40']
- x: 20
- y: 40
- shape: TRIANGLE
- size: 20
"""
def __init__(self, exprs, savelist=True):
super(Each, self).__init__(exprs, savelist)
self.mayReturnEmpty = all(e.mayReturnEmpty for e in self.exprs)
self.skipWhitespace = True
self.initExprGroups = True
self.saveAsList = True
def streamline(self):
super(Each, self).streamline()
self.mayReturnEmpty = all(e.mayReturnEmpty for e in self.exprs)
return self
def parseImpl(self, instring, loc, doActions=True):
if self.initExprGroups:
self.opt1map = dict((id(e.expr), e) for e in self.exprs if isinstance(e, Optional))
opt1 = [e.expr for e in self.exprs if isinstance(e, Optional)]
opt2 = [e for e in self.exprs if e.mayReturnEmpty and not isinstance(e, (Optional, Regex))]
self.optionals = opt1 + opt2
self.multioptionals = [e.expr for e in self.exprs if isinstance(e, ZeroOrMore)]
self.multirequired = [e.expr for e in self.exprs if isinstance(e, OneOrMore)]
self.required = [e for e in self.exprs if not isinstance(e, (Optional, ZeroOrMore, OneOrMore))]
self.required += self.multirequired
self.initExprGroups = False
tmpLoc = loc
tmpReqd = self.required[:]
tmpOpt = self.optionals[:]
matchOrder = []
keepMatching = True
while keepMatching:
tmpExprs = tmpReqd + tmpOpt + self.multioptionals + self.multirequired
failed = []
for e in tmpExprs:
try:
tmpLoc = e.tryParse(instring, tmpLoc)
except ParseException:
failed.append(e)
else:
matchOrder.append(self.opt1map.get(id(e), e))
if e in tmpReqd:
tmpReqd.remove(e)
elif e in tmpOpt:
tmpOpt.remove(e)
if len(failed) == len(tmpExprs):
keepMatching = False
if tmpReqd:
missing = ", ".join(_ustr(e) for e in tmpReqd)
raise ParseException(instring, loc, "Missing one or more required elements (%s)" % missing)
# add any unmatched Optionals, in case they have default values defined
matchOrder += [e for e in self.exprs if isinstance(e, Optional) and e.expr in tmpOpt]
resultlist = []
for e in matchOrder:
loc, results = e._parse(instring, loc, doActions)
resultlist.append(results)
finalResults = sum(resultlist, ParseResults([]))
return loc, finalResults
def __str__(self):
if hasattr(self, "name"):
return self.name
if self.strRepr is None:
self.strRepr = "{" + " & ".join(_ustr(e) for e in self.exprs) + "}"
return self.strRepr
def checkRecursion(self, parseElementList):
subRecCheckList = parseElementList[:] + [self]
for e in self.exprs:
e.checkRecursion(subRecCheckList)
class ParseElementEnhance(ParserElement):
"""Abstract subclass of :class:`ParserElement`, for combining and
post-processing parsed tokens.
"""
def __init__(self, expr, savelist=False):
super(ParseElementEnhance, self).__init__(savelist)
if isinstance(expr, basestring):
if issubclass(self._literalStringClass, Token):
expr = self._literalStringClass(expr)
else:
expr = self._literalStringClass(Literal(expr))
self.expr = expr
self.strRepr = None
if expr is not None:
self.mayIndexError = expr.mayIndexError
self.mayReturnEmpty = expr.mayReturnEmpty
self.setWhitespaceChars(expr.whiteChars)
self.skipWhitespace = expr.skipWhitespace
self.saveAsList = expr.saveAsList
self.callPreparse = expr.callPreparse
self.ignoreExprs.extend(expr.ignoreExprs)
def parseImpl(self, instring, loc, doActions=True):
if self.expr is not None:
return self.expr._parse(instring, loc, doActions, callPreParse=False)
else:
raise ParseException("", loc, self.errmsg, self)
def leaveWhitespace(self):
self.skipWhitespace = False
self.expr = self.expr.copy()
if self.expr is not None:
self.expr.leaveWhitespace()
return self
def ignore(self, other):
if isinstance(other, Suppress):
if other not in self.ignoreExprs:
super(ParseElementEnhance, self).ignore(other)
if self.expr is not None:
self.expr.ignore(self.ignoreExprs[-1])
else:
super(ParseElementEnhance, self).ignore(other)
if self.expr is not None:
self.expr.ignore(self.ignoreExprs[-1])
return self
def streamline(self):
super(ParseElementEnhance, self).streamline()
if self.expr is not None:
self.expr.streamline()
return self
def checkRecursion(self, parseElementList):
if self in parseElementList:
raise RecursiveGrammarException(parseElementList + [self])
subRecCheckList = parseElementList[:] + [self]
if self.expr is not None:
self.expr.checkRecursion(subRecCheckList)
def validate(self, validateTrace=None):
if validateTrace is None:
validateTrace = []
tmp = validateTrace[:] + [self]
if self.expr is not None:
self.expr.validate(tmp)
self.checkRecursion([])
def __str__(self):
try:
return super(ParseElementEnhance, self).__str__()
except Exception:
pass
if self.strRepr is None and self.expr is not None:
self.strRepr = "%s:(%s)" % (self.__class__.__name__, _ustr(self.expr))
return self.strRepr
class FollowedBy(ParseElementEnhance):
"""Lookahead matching of the given parse expression.
``FollowedBy`` does *not* advance the parsing position within
the input string, it only verifies that the specified parse
expression matches at the current position. ``FollowedBy``
always returns a null token list. If any results names are defined
in the lookahead expression, those *will* be returned for access by
name.
Example::
# use FollowedBy to match a label only if it is followed by a ':'
data_word = Word(alphas)
label = data_word + FollowedBy(':')
attr_expr = Group(label + Suppress(':') + OneOrMore(data_word, stopOn=label).setParseAction(' '.join))
OneOrMore(attr_expr).parseString("shape: SQUARE color: BLACK posn: upper left").pprint()
prints::
[['shape', 'SQUARE'], ['color', 'BLACK'], ['posn', 'upper left']]
"""
def __init__(self, expr):
super(FollowedBy, self).__init__(expr)
self.mayReturnEmpty = True
def parseImpl(self, instring, loc, doActions=True):
# by using self._expr.parse and deleting the contents of the returned ParseResults list
# we keep any named results that were defined in the FollowedBy expression
_, ret = self.expr._parse(instring, loc, doActions=doActions)
del ret[:]
return loc, ret
class PrecededBy(ParseElementEnhance):
"""Lookbehind matching of the given parse expression.
``PrecededBy`` does not advance the parsing position within the
input string, it only verifies that the specified parse expression
matches prior to the current position. ``PrecededBy`` always
returns a null token list, but if a results name is defined on the
given expression, it is returned.
Parameters:
- expr - expression that must match prior to the current parse
location
- retreat - (default= ``None``) - (int) maximum number of characters
to lookbehind prior to the current parse location
If the lookbehind expression is a string, Literal, Keyword, or
a Word or CharsNotIn with a specified exact or maximum length, then
the retreat parameter is not required. Otherwise, retreat must be
specified to give a maximum number of characters to look back from
the current parse position for a lookbehind match.
Example::
# VB-style variable names with type prefixes
int_var = PrecededBy("#") + pyparsing_common.identifier
str_var = PrecededBy("$") + pyparsing_common.identifier
"""
def __init__(self, expr, retreat=None):
super(PrecededBy, self).__init__(expr)
self.expr = self.expr().leaveWhitespace()
self.mayReturnEmpty = True
self.mayIndexError = False
self.exact = False
if isinstance(expr, str):
retreat = len(expr)
self.exact = True
elif isinstance(expr, (Literal, Keyword)):
retreat = expr.matchLen
self.exact = True
elif isinstance(expr, (Word, CharsNotIn)) and expr.maxLen != _MAX_INT:
retreat = expr.maxLen
self.exact = True
elif isinstance(expr, _PositionToken):
retreat = 0
self.exact = True
self.retreat = retreat
self.errmsg = "not preceded by " + str(expr)
self.skipWhitespace = False
self.parseAction.append(lambda s, l, t: t.__delitem__(slice(None, None)))
def parseImpl(self, instring, loc=0, doActions=True):
if self.exact:
if loc < self.retreat:
raise ParseException(instring, loc, self.errmsg)
start = loc - self.retreat
_, ret = self.expr._parse(instring, start)
else:
# retreat specified a maximum lookbehind window, iterate
test_expr = self.expr + StringEnd()
instring_slice = instring[max(0, loc - self.retreat):loc]
last_expr = ParseException(instring, loc, self.errmsg)
for offset in range(1, min(loc, self.retreat + 1)+1):
try:
# print('trying', offset, instring_slice, repr(instring_slice[loc - offset:]))
_, ret = test_expr._parse(instring_slice, len(instring_slice) - offset)
except ParseBaseException as pbe:
last_expr = pbe
else:
break
else:
raise last_expr
return loc, ret
class NotAny(ParseElementEnhance):
"""Lookahead to disallow matching with the given parse expression.
``NotAny`` does *not* advance the parsing position within the
input string, it only verifies that the specified parse expression
does *not* match at the current position. Also, ``NotAny`` does
*not* skip over leading whitespace. ``NotAny`` always returns
a null token list. May be constructed using the '~' operator.
Example::
AND, OR, NOT = map(CaselessKeyword, "AND OR NOT".split())
# take care not to mistake keywords for identifiers
ident = ~(AND | OR | NOT) + Word(alphas)
boolean_term = Optional(NOT) + ident
# very crude boolean expression - to support parenthesis groups and
# operation hierarchy, use infixNotation
boolean_expr = boolean_term + ZeroOrMore((AND | OR) + boolean_term)
# integers that are followed by "." are actually floats
integer = Word(nums) + ~Char(".")
"""
def __init__(self, expr):
super(NotAny, self).__init__(expr)
# ~ self.leaveWhitespace()
self.skipWhitespace = False # do NOT use self.leaveWhitespace(), don't want to propagate to exprs
self.mayReturnEmpty = True
self.errmsg = "Found unwanted token, " + _ustr(self.expr)
def parseImpl(self, instring, loc, doActions=True):
if self.expr.canParseNext(instring, loc):
raise ParseException(instring, loc, self.errmsg, self)
return loc, []
def __str__(self):
if hasattr(self, "name"):
return self.name
if self.strRepr is None:
self.strRepr = "~{" + _ustr(self.expr) + "}"
return self.strRepr
class _MultipleMatch(ParseElementEnhance):
def __init__(self, expr, stopOn=None):
super(_MultipleMatch, self).__init__(expr)
self.saveAsList = True
ender = stopOn
if isinstance(ender, basestring):
ender = self._literalStringClass(ender)
self.stopOn(ender)
def stopOn(self, ender):
if isinstance(ender, basestring):
ender = self._literalStringClass(ender)
self.not_ender = ~ender if ender is not None else None
return self
def parseImpl(self, instring, loc, doActions=True):
self_expr_parse = self.expr._parse
self_skip_ignorables = self._skipIgnorables
check_ender = self.not_ender is not None
if check_ender:
try_not_ender = self.not_ender.tryParse
# must be at least one (but first see if we are the stopOn sentinel;
# if so, fail)
if check_ender:
try_not_ender(instring, loc)
loc, tokens = self_expr_parse(instring, loc, doActions, callPreParse=False)
try:
hasIgnoreExprs = (not not self.ignoreExprs)
while 1:
if check_ender:
try_not_ender(instring, loc)
if hasIgnoreExprs:
preloc = self_skip_ignorables(instring, loc)
else:
preloc = loc
loc, tmptokens = self_expr_parse(instring, preloc, doActions)
if tmptokens or tmptokens.haskeys():
tokens += tmptokens
except (ParseException, IndexError):
pass
return loc, tokens
def _setResultsName(self, name, listAllMatches=False):
if __diag__.warn_ungrouped_named_tokens_in_collection:
for e in [self.expr] + getattr(self.expr, 'exprs', []):
if isinstance(e, ParserElement) and e.resultsName:
warnings.warn("{0}: setting results name {1!r} on {2} expression "
"collides with {3!r} on contained expression".format("warn_ungrouped_named_tokens_in_collection",
name,
type(self).__name__,
e.resultsName),
stacklevel=3)
return super(_MultipleMatch, self)._setResultsName(name, listAllMatches)
class OneOrMore(_MultipleMatch):
"""Repetition of one or more of the given expression.
Parameters:
- expr - expression that must match one or more times
- stopOn - (default= ``None``) - expression for a terminating sentinel
(only required if the sentinel would ordinarily match the repetition
expression)
Example::
data_word = Word(alphas)
label = data_word + FollowedBy(':')
attr_expr = Group(label + Suppress(':') + OneOrMore(data_word).setParseAction(' '.join))
text = "shape: SQUARE posn: upper left color: BLACK"
OneOrMore(attr_expr).parseString(text).pprint() # Fail! read 'color' as data instead of next label -> [['shape', 'SQUARE color']]
# use stopOn attribute for OneOrMore to avoid reading label string as part of the data
attr_expr = Group(label + Suppress(':') + OneOrMore(data_word, stopOn=label).setParseAction(' '.join))
OneOrMore(attr_expr).parseString(text).pprint() # Better -> [['shape', 'SQUARE'], ['posn', 'upper left'], ['color', 'BLACK']]
# could also be written as
(attr_expr * (1,)).parseString(text).pprint()
"""
def __str__(self):
if hasattr(self, "name"):
return self.name
if self.strRepr is None:
self.strRepr = "{" + _ustr(self.expr) + "}..."
return self.strRepr
class ZeroOrMore(_MultipleMatch):
"""Optional repetition of zero or more of the given expression.
Parameters:
- expr - expression that must match zero or more times
- stopOn - (default= ``None``) - expression for a terminating sentinel
(only required if the sentinel would ordinarily match the repetition
expression)
Example: similar to :class:`OneOrMore`
"""
def __init__(self, expr, stopOn=None):
super(ZeroOrMore, self).__init__(expr, stopOn=stopOn)
self.mayReturnEmpty = True
def parseImpl(self, instring, loc, doActions=True):
try:
return super(ZeroOrMore, self).parseImpl(instring, loc, doActions)
except (ParseException, IndexError):
return loc, []
def __str__(self):
if hasattr(self, "name"):
return self.name
if self.strRepr is None:
self.strRepr = "[" + _ustr(self.expr) + "]..."
return self.strRepr
class _NullToken(object):
def __bool__(self):
return False
__nonzero__ = __bool__
def __str__(self):
return ""
class Optional(ParseElementEnhance):
"""Optional matching of the given expression.
Parameters:
- expr - expression that must match zero or more times
- default (optional) - value to be returned if the optional expression is not found.
Example::
# US postal code can be a 5-digit zip, plus optional 4-digit qualifier
zip = Combine(Word(nums, exact=5) + Optional('-' + Word(nums, exact=4)))
zip.runTests('''
# traditional ZIP code
12345
# ZIP+4 form
12101-0001
# invalid ZIP
98765-
''')
prints::
# traditional ZIP code
12345
['12345']
# ZIP+4 form
12101-0001
['12101-0001']
# invalid ZIP
98765-
^
FAIL: Expected end of text (at char 5), (line:1, col:6)
"""
__optionalNotMatched = _NullToken()
def __init__(self, expr, default=__optionalNotMatched):
super(Optional, self).__init__(expr, savelist=False)
self.saveAsList = self.expr.saveAsList
self.defaultValue = default
self.mayReturnEmpty = True
def parseImpl(self, instring, loc, doActions=True):
try:
loc, tokens = self.expr._parse(instring, loc, doActions, callPreParse=False)
except (ParseException, IndexError):
if self.defaultValue is not self.__optionalNotMatched:
if self.expr.resultsName:
tokens = ParseResults([self.defaultValue])
tokens[self.expr.resultsName] = self.defaultValue
else:
tokens = [self.defaultValue]
else:
tokens = []
return loc, tokens
def __str__(self):
if hasattr(self, "name"):
return self.name
if self.strRepr is None:
self.strRepr = "[" + _ustr(self.expr) + "]"
return self.strRepr
class SkipTo(ParseElementEnhance):
"""Token for skipping over all undefined text until the matched
expression is found.
Parameters:
- expr - target expression marking the end of the data to be skipped
- include - (default= ``False``) if True, the target expression is also parsed
(the skipped text and target expression are returned as a 2-element list).
- ignore - (default= ``None``) used to define grammars (typically quoted strings and
comments) that might contain false matches to the target expression
- failOn - (default= ``None``) define expressions that are not allowed to be
included in the skipped test; if found before the target expression is found,
the SkipTo is not a match
Example::
report = '''
Outstanding Issues Report - 1 Jan 2000
# | Severity | Description | Days Open
-----+----------+-------------------------------------------+-----------
101 | Critical | Intermittent system crash | 6
94 | Cosmetic | Spelling error on Login ('log|n') | 14
79 | Minor | System slow when running too many reports | 47
'''
integer = Word(nums)
SEP = Suppress('|')
# use SkipTo to simply match everything up until the next SEP
# - ignore quoted strings, so that a '|' character inside a quoted string does not match
# - parse action will call token.strip() for each matched token, i.e., the description body
string_data = SkipTo(SEP, ignore=quotedString)
string_data.setParseAction(tokenMap(str.strip))
ticket_expr = (integer("issue_num") + SEP
+ string_data("sev") + SEP
+ string_data("desc") + SEP
+ integer("days_open"))
for tkt in ticket_expr.searchString(report):
print tkt.dump()
prints::
['101', 'Critical', 'Intermittent system crash', '6']
- days_open: 6
- desc: Intermittent system crash
- issue_num: 101
- sev: Critical
['94', 'Cosmetic', "Spelling error on Login ('log|n')", '14']
- days_open: 14
- desc: Spelling error on Login ('log|n')
- issue_num: 94
- sev: Cosmetic
['79', 'Minor', 'System slow when running too many reports', '47']
- days_open: 47
- desc: System slow when running too many reports
- issue_num: 79
- sev: Minor
"""
def __init__(self, other, include=False, ignore=None, failOn=None):
super(SkipTo, self).__init__(other)
self.ignoreExpr = ignore
self.mayReturnEmpty = True
self.mayIndexError = False
self.includeMatch = include
self.saveAsList = False
if isinstance(failOn, basestring):
self.failOn = self._literalStringClass(failOn)
else:
self.failOn = failOn
self.errmsg = "No match found for " + _ustr(self.expr)
def parseImpl(self, instring, loc, doActions=True):
startloc = loc
instrlen = len(instring)
expr = self.expr
expr_parse = self.expr._parse
self_failOn_canParseNext = self.failOn.canParseNext if self.failOn is not None else None
self_ignoreExpr_tryParse = self.ignoreExpr.tryParse if self.ignoreExpr is not None else None
tmploc = loc
while tmploc <= instrlen:
if self_failOn_canParseNext is not None:
# break if failOn expression matches
if self_failOn_canParseNext(instring, tmploc):
break
if self_ignoreExpr_tryParse is not None:
# advance past ignore expressions
while 1:
try:
tmploc = self_ignoreExpr_tryParse(instring, tmploc)
except ParseBaseException:
break
try:
expr_parse(instring, tmploc, doActions=False, callPreParse=False)
except (ParseException, IndexError):
# no match, advance loc in string
tmploc += 1
else:
# matched skipto expr, done
break
else:
# ran off the end of the input string without matching skipto expr, fail
raise ParseException(instring, loc, self.errmsg, self)
# build up return values
loc = tmploc
skiptext = instring[startloc:loc]
skipresult = ParseResults(skiptext)
if self.includeMatch:
loc, mat = expr_parse(instring, loc, doActions, callPreParse=False)
skipresult += mat
return loc, skipresult
class Forward(ParseElementEnhance):
"""Forward declaration of an expression to be defined later -
used for recursive grammars, such as algebraic infix notation.
When the expression is known, it is assigned to the ``Forward``
variable using the '<<' operator.
Note: take care when assigning to ``Forward`` not to overlook
precedence of operators.
Specifically, '|' has a lower precedence than '<<', so that::
fwdExpr << a | b | c
will actually be evaluated as::
(fwdExpr << a) | b | c
thereby leaving b and c out as parseable alternatives. It is recommended that you
explicitly group the values inserted into the ``Forward``::
fwdExpr << (a | b | c)
Converting to use the '<<=' operator instead will avoid this problem.
See :class:`ParseResults.pprint` for an example of a recursive
parser created using ``Forward``.
"""
def __init__(self, other=None):
super(Forward, self).__init__(other, savelist=False)
def __lshift__(self, other):
if isinstance(other, basestring):
other = self._literalStringClass(other)
self.expr = other
self.strRepr = None
self.mayIndexError = self.expr.mayIndexError
self.mayReturnEmpty = self.expr.mayReturnEmpty
self.setWhitespaceChars(self.expr.whiteChars)
self.skipWhitespace = self.expr.skipWhitespace
self.saveAsList = self.expr.saveAsList
self.ignoreExprs.extend(self.expr.ignoreExprs)
return self
def __ilshift__(self, other):
return self << other
def leaveWhitespace(self):
self.skipWhitespace = False
return self
def streamline(self):
if not self.streamlined:
self.streamlined = True
if self.expr is not None:
self.expr.streamline()
return self
def validate(self, validateTrace=None):
if validateTrace is None:
validateTrace = []
if self not in validateTrace:
tmp = validateTrace[:] + [self]
if self.expr is not None:
self.expr.validate(tmp)
self.checkRecursion([])
def __str__(self):
if hasattr(self, "name"):
return self.name
if self.strRepr is not None:
return self.strRepr
# Avoid infinite recursion by setting a temporary strRepr
self.strRepr = ": ..."
# Use the string representation of main expression.
retString = '...'
try:
if self.expr is not None:
retString = _ustr(self.expr)[:1000]
else:
retString = "None"
finally:
self.strRepr = self.__class__.__name__ + ": " + retString
return self.strRepr
def copy(self):
if self.expr is not None:
return super(Forward, self).copy()
else:
ret = Forward()
ret <<= self
return ret
def _setResultsName(self, name, listAllMatches=False):
if __diag__.warn_name_set_on_empty_Forward:
if self.expr is None:
warnings.warn("{0}: setting results name {0!r} on {1} expression "
"that has no contained expression".format("warn_name_set_on_empty_Forward",
name,
type(self).__name__),
stacklevel=3)
return super(Forward, self)._setResultsName(name, listAllMatches)
class TokenConverter(ParseElementEnhance):
"""
Abstract subclass of :class:`ParseExpression`, for converting parsed results.
"""
def __init__(self, expr, savelist=False):
super(TokenConverter, self).__init__(expr) # , savelist)
self.saveAsList = False
class Combine(TokenConverter):
"""Converter to concatenate all matching tokens to a single string.
By default, the matching patterns must also be contiguous in the
input string; this can be disabled by specifying
``'adjacent=False'`` in the constructor.
Example::
real = Word(nums) + '.' + Word(nums)
print(real.parseString('3.1416')) # -> ['3', '.', '1416']
# will also erroneously match the following
print(real.parseString('3. 1416')) # -> ['3', '.', '1416']
real = Combine(Word(nums) + '.' + Word(nums))
print(real.parseString('3.1416')) # -> ['3.1416']
# no match when there are internal spaces
print(real.parseString('3. 1416')) # -> Exception: Expected W:(0123...)
"""
def __init__(self, expr, joinString="", adjacent=True):
super(Combine, self).__init__(expr)
# suppress whitespace-stripping in contained parse expressions, but re-enable it on the Combine itself
if adjacent:
self.leaveWhitespace()
self.adjacent = adjacent
self.skipWhitespace = True
self.joinString = joinString
self.callPreparse = True
def ignore(self, other):
if self.adjacent:
ParserElement.ignore(self, other)
else:
super(Combine, self).ignore(other)
return self
def postParse(self, instring, loc, tokenlist):
retToks = tokenlist.copy()
del retToks[:]
retToks += ParseResults(["".join(tokenlist._asStringList(self.joinString))], modal=self.modalResults)
if self.resultsName and retToks.haskeys():
return [retToks]
else:
return retToks
class Group(TokenConverter):
"""Converter to return the matched tokens as a list - useful for
returning tokens of :class:`ZeroOrMore` and :class:`OneOrMore` expressions.
Example::
ident = Word(alphas)
num = Word(nums)
term = ident | num
func = ident + Optional(delimitedList(term))
print(func.parseString("fn a, b, 100")) # -> ['fn', 'a', 'b', '100']
func = ident + Group(Optional(delimitedList(term)))
print(func.parseString("fn a, b, 100")) # -> ['fn', ['a', 'b', '100']]
"""
def __init__(self, expr):
super(Group, self).__init__(expr)
self.saveAsList = True
def postParse(self, instring, loc, tokenlist):
return [tokenlist]
class Dict(TokenConverter):
"""Converter to return a repetitive expression as a list, but also
as a dictionary. Each element can also be referenced using the first
token in the expression as its key. Useful for tabular report
scraping when the first column can be used as a item key.
Example::
data_word = Word(alphas)
label = data_word + FollowedBy(':')
attr_expr = Group(label + Suppress(':') + OneOrMore(data_word).setParseAction(' '.join))
text = "shape: SQUARE posn: upper left color: light blue texture: burlap"
attr_expr = (label + Suppress(':') + OneOrMore(data_word, stopOn=label).setParseAction(' '.join))
# print attributes as plain groups
print(OneOrMore(attr_expr).parseString(text).dump())
# instead of OneOrMore(expr), parse using Dict(OneOrMore(Group(expr))) - Dict will auto-assign names
result = Dict(OneOrMore(Group(attr_expr))).parseString(text)
print(result.dump())
# access named fields as dict entries, or output as dict
print(result['shape'])
print(result.asDict())
prints::
['shape', 'SQUARE', 'posn', 'upper left', 'color', 'light blue', 'texture', 'burlap']
[['shape', 'SQUARE'], ['posn', 'upper left'], ['color', 'light blue'], ['texture', 'burlap']]
- color: light blue
- posn: upper left
- shape: SQUARE
- texture: burlap
SQUARE
{'color': 'light blue', 'posn': 'upper left', 'texture': 'burlap', 'shape': 'SQUARE'}
See more examples at :class:`ParseResults` of accessing fields by results name.
"""
def __init__(self, expr):
super(Dict, self).__init__(expr)
self.saveAsList = True
def postParse(self, instring, loc, tokenlist):
for i, tok in enumerate(tokenlist):
if len(tok) == 0:
continue
ikey = tok[0]
if isinstance(ikey, int):
ikey = _ustr(tok[0]).strip()
if len(tok) == 1:
tokenlist[ikey] = _ParseResultsWithOffset("", i)
elif len(tok) == 2 and not isinstance(tok[1], ParseResults):
tokenlist[ikey] = _ParseResultsWithOffset(tok[1], i)
else:
dictvalue = tok.copy() # ParseResults(i)
del dictvalue[0]
if len(dictvalue) != 1 or (isinstance(dictvalue, ParseResults) and dictvalue.haskeys()):
tokenlist[ikey] = _ParseResultsWithOffset(dictvalue, i)
else:
tokenlist[ikey] = _ParseResultsWithOffset(dictvalue[0], i)
if self.resultsName:
return [tokenlist]
else:
return tokenlist
class Suppress(TokenConverter):
"""Converter for ignoring the results of a parsed expression.
Example::
source = "a, b, c,d"
wd = Word(alphas)
wd_list1 = wd + ZeroOrMore(',' + wd)
print(wd_list1.parseString(source))
# often, delimiters that are useful during parsing are just in the
# way afterward - use Suppress to keep them out of the parsed output
wd_list2 = wd + ZeroOrMore(Suppress(',') + wd)
print(wd_list2.parseString(source))
prints::
['a', ',', 'b', ',', 'c', ',', 'd']
['a', 'b', 'c', 'd']
(See also :class:`delimitedList`.)
"""
def postParse(self, instring, loc, tokenlist):
return []
def suppress(self):
return self
class OnlyOnce(object):
"""Wrapper for parse actions, to ensure they are only called once.
"""
def __init__(self, methodCall):
self.callable = _trim_arity(methodCall)
self.called = False
def __call__(self, s, l, t):
if not self.called:
results = self.callable(s, l, t)
self.called = True
return results
raise ParseException(s, l, "")
def reset(self):
self.called = False
def traceParseAction(f):
"""Decorator for debugging parse actions.
When the parse action is called, this decorator will print
``">> entering method-name(line:<current_source_line>, <parse_location>, <matched_tokens>)"``.
When the parse action completes, the decorator will print
``"<<"`` followed by the returned value, or any exception that the parse action raised.
Example::
wd = Word(alphas)
@traceParseAction
def remove_duplicate_chars(tokens):
return ''.join(sorted(set(''.join(tokens))))
wds = OneOrMore(wd).setParseAction(remove_duplicate_chars)
print(wds.parseString("slkdjs sld sldd sdlf sdljf"))
prints::
>>entering remove_duplicate_chars(line: 'slkdjs sld sldd sdlf sdljf', 0, (['slkdjs', 'sld', 'sldd', 'sdlf', 'sdljf'], {}))
<<leaving remove_duplicate_chars (ret: 'dfjkls')
['dfjkls']
"""
f = _trim_arity(f)
def z(*paArgs):
thisFunc = f.__name__
s, l, t = paArgs[-3:]
if len(paArgs) > 3:
thisFunc = paArgs[0].__class__.__name__ + '.' + thisFunc
sys.stderr.write(">>entering %s(line: '%s', %d, %r)\n" % (thisFunc, line(l, s), l, t))
try:
ret = f(*paArgs)
except Exception as exc:
sys.stderr.write("<<leaving %s (exception: %s)\n" % (thisFunc, exc))
raise
sys.stderr.write("<<leaving %s (ret: %r)\n" % (thisFunc, ret))
return ret
try:
z.__name__ = f.__name__
except AttributeError:
pass
return z
#
# global helpers
#
def delimitedList(expr, delim=",", combine=False):
"""Helper to define a delimited list of expressions - the delimiter
defaults to ','. By default, the list elements and delimiters can
have intervening whitespace, and comments, but this can be
overridden by passing ``combine=True`` in the constructor. If
``combine`` is set to ``True``, the matching tokens are
returned as a single token string, with the delimiters included;
otherwise, the matching tokens are returned as a list of tokens,
with the delimiters suppressed.
Example::
delimitedList(Word(alphas)).parseString("aa,bb,cc") # -> ['aa', 'bb', 'cc']
delimitedList(Word(hexnums), delim=':', combine=True).parseString("AA:BB:CC:DD:EE") # -> ['AA:BB:CC:DD:EE']
"""
dlName = _ustr(expr) + " [" + _ustr(delim) + " " + _ustr(expr) + "]..."
if combine:
return Combine(expr + ZeroOrMore(delim + expr)).setName(dlName)
else:
return (expr + ZeroOrMore(Suppress(delim) + expr)).setName(dlName)
def countedArray(expr, intExpr=None):
"""Helper to define a counted list of expressions.
This helper defines a pattern of the form::
integer expr expr expr...
where the leading integer tells how many expr expressions follow.
The matched tokens returns the array of expr tokens as a list - the
leading count token is suppressed.
If ``intExpr`` is specified, it should be a pyparsing expression
that produces an integer value.
Example::
countedArray(Word(alphas)).parseString('2 ab cd ef') # -> ['ab', 'cd']
# in this parser, the leading integer value is given in binary,
# '10' indicating that 2 values are in the array
binaryConstant = Word('01').setParseAction(lambda t: int(t[0], 2))
countedArray(Word(alphas), intExpr=binaryConstant).parseString('10 ab cd ef') # -> ['ab', 'cd']
"""
arrayExpr = Forward()
def countFieldParseAction(s, l, t):
n = t[0]
arrayExpr << (n and Group(And([expr] * n)) or Group(empty))
return []
if intExpr is None:
intExpr = Word(nums).setParseAction(lambda t: int(t[0]))
else:
intExpr = intExpr.copy()
intExpr.setName("arrayLen")
intExpr.addParseAction(countFieldParseAction, callDuringTry=True)
return (intExpr + arrayExpr).setName('(len) ' + _ustr(expr) + '...')
def _flatten(L):
ret = []
for i in L:
if isinstance(i, list):
ret.extend(_flatten(i))
else:
ret.append(i)
return ret
def matchPreviousLiteral(expr):
"""Helper to define an expression that is indirectly defined from
the tokens matched in a previous expression, that is, it looks for
a 'repeat' of a previous expression. For example::
first = Word(nums)
second = matchPreviousLiteral(first)
matchExpr = first + ":" + second
will match ``"1:1"``, but not ``"1:2"``. Because this
matches a previous literal, will also match the leading
``"1:1"`` in ``"1:10"``. If this is not desired, use
:class:`matchPreviousExpr`. Do *not* use with packrat parsing
enabled.
"""
rep = Forward()
def copyTokenToRepeater(s, l, t):
if t:
if len(t) == 1:
rep << t[0]
else:
# flatten t tokens
tflat = _flatten(t.asList())
rep << And(Literal(tt) for tt in tflat)
else:
rep << Empty()
expr.addParseAction(copyTokenToRepeater, callDuringTry=True)
rep.setName('(prev) ' + _ustr(expr))
return rep
def matchPreviousExpr(expr):
"""Helper to define an expression that is indirectly defined from
the tokens matched in a previous expression, that is, it looks for
a 'repeat' of a previous expression. For example::
first = Word(nums)
second = matchPreviousExpr(first)
matchExpr = first + ":" + second
will match ``"1:1"``, but not ``"1:2"``. Because this
matches by expressions, will *not* match the leading ``"1:1"``
in ``"1:10"``; the expressions are evaluated first, and then
compared, so ``"1"`` is compared with ``"10"``. Do *not* use
with packrat parsing enabled.
"""
rep = Forward()
e2 = expr.copy()
rep <<= e2
def copyTokenToRepeater(s, l, t):
matchTokens = _flatten(t.asList())
def mustMatchTheseTokens(s, l, t):
theseTokens = _flatten(t.asList())
if theseTokens != matchTokens:
raise ParseException('', 0, '')
rep.setParseAction(mustMatchTheseTokens, callDuringTry=True)
expr.addParseAction(copyTokenToRepeater, callDuringTry=True)
rep.setName('(prev) ' + _ustr(expr))
return rep
def _escapeRegexRangeChars(s):
# ~ escape these chars: ^-[]
for c in r"\^-[]":
s = s.replace(c, _bslash + c)
s = s.replace("\n", r"\n")
s = s.replace("\t", r"\t")
return _ustr(s)
def oneOf(strs, caseless=False, useRegex=True, asKeyword=False):
"""Helper to quickly define a set of alternative Literals, and makes
sure to do longest-first testing when there is a conflict,
regardless of the input order, but returns
a :class:`MatchFirst` for best performance.
Parameters:
- strs - a string of space-delimited literals, or a collection of
string literals
- caseless - (default= ``False``) - treat all literals as
caseless
- useRegex - (default= ``True``) - as an optimization, will
generate a Regex object; otherwise, will generate
a :class:`MatchFirst` object (if ``caseless=True`` or ``asKeyword=True``, or if
creating a :class:`Regex` raises an exception)
- asKeyword - (default=``False``) - enforce Keyword-style matching on the
generated expressions
Example::
comp_oper = oneOf("< = > <= >= !=")
var = Word(alphas)
number = Word(nums)
term = var | number
comparison_expr = term + comp_oper + term
print(comparison_expr.searchString("B = 12 AA=23 B<=AA AA>12"))
prints::
[['B', '=', '12'], ['AA', '=', '23'], ['B', '<=', 'AA'], ['AA', '>', '12']]
"""
if isinstance(caseless, basestring):
warnings.warn("More than one string argument passed to oneOf, pass "
"choices as a list or space-delimited string", stacklevel=2)
if caseless:
isequal = (lambda a, b: a.upper() == b.upper())
masks = (lambda a, b: b.upper().startswith(a.upper()))
parseElementClass = CaselessKeyword if asKeyword else CaselessLiteral
else:
isequal = (lambda a, b: a == b)
masks = (lambda a, b: b.startswith(a))
parseElementClass = Keyword if asKeyword else Literal
symbols = []
if isinstance(strs, basestring):
symbols = strs.split()
elif isinstance(strs, Iterable):
symbols = list(strs)
else:
warnings.warn("Invalid argument to oneOf, expected string or iterable",
SyntaxWarning, stacklevel=2)
if not symbols:
return NoMatch()
if not asKeyword:
# if not producing keywords, need to reorder to take care to avoid masking
# longer choices with shorter ones
i = 0
while i < len(symbols) - 1:
cur = symbols[i]
for j, other in enumerate(symbols[i + 1:]):
if isequal(other, cur):
del symbols[i + j + 1]
break
elif masks(cur, other):
del symbols[i + j + 1]
symbols.insert(i, other)
break
else:
i += 1
if not (caseless or asKeyword) and useRegex:
# ~ print (strs, "->", "|".join([_escapeRegexChars(sym) for sym in symbols]))
try:
if len(symbols) == len("".join(symbols)):
return Regex("[%s]" % "".join(_escapeRegexRangeChars(sym) for sym in symbols)).setName(' | '.join(symbols))
else:
return Regex("|".join(re.escape(sym) for sym in symbols)).setName(' | '.join(symbols))
except Exception:
warnings.warn("Exception creating Regex for oneOf, building MatchFirst",
SyntaxWarning, stacklevel=2)
# last resort, just use MatchFirst
return MatchFirst(parseElementClass(sym) for sym in symbols).setName(' | '.join(symbols))
def dictOf(key, value):
"""Helper to easily and clearly define a dictionary by specifying
the respective patterns for the key and value. Takes care of
defining the :class:`Dict`, :class:`ZeroOrMore`, and
:class:`Group` tokens in the proper order. The key pattern
can include delimiting markers or punctuation, as long as they are
suppressed, thereby leaving the significant key text. The value
pattern can include named results, so that the :class:`Dict` results
can include named token fields.
Example::
text = "shape: SQUARE posn: upper left color: light blue texture: burlap"
attr_expr = (label + Suppress(':') + OneOrMore(data_word, stopOn=label).setParseAction(' '.join))
print(OneOrMore(attr_expr).parseString(text).dump())
attr_label = label
attr_value = Suppress(':') + OneOrMore(data_word, stopOn=label).setParseAction(' '.join)
# similar to Dict, but simpler call format
result = dictOf(attr_label, attr_value).parseString(text)
print(result.dump())
print(result['shape'])
print(result.shape) # object attribute access works too
print(result.asDict())
prints::
[['shape', 'SQUARE'], ['posn', 'upper left'], ['color', 'light blue'], ['texture', 'burlap']]
- color: light blue
- posn: upper left
- shape: SQUARE
- texture: burlap
SQUARE
SQUARE
{'color': 'light blue', 'shape': 'SQUARE', 'posn': 'upper left', 'texture': 'burlap'}
"""
return Dict(OneOrMore(Group(key + value)))
def originalTextFor(expr, asString=True):
"""Helper to return the original, untokenized text for a given
expression. Useful to restore the parsed fields of an HTML start
tag into the raw tag text itself, or to revert separate tokens with
intervening whitespace back to the original matching input text. By
default, returns astring containing the original parsed text.
If the optional ``asString`` argument is passed as
``False``, then the return value is
a :class:`ParseResults` containing any results names that
were originally matched, and a single token containing the original
matched text from the input string. So if the expression passed to
:class:`originalTextFor` contains expressions with defined
results names, you must set ``asString`` to ``False`` if you
want to preserve those results name values.
Example::
src = "this is test <b> bold <i>text</i> </b> normal text "
for tag in ("b", "i"):
opener, closer = makeHTMLTags(tag)
patt = originalTextFor(opener + SkipTo(closer) + closer)
print(patt.searchString(src)[0])
prints::
['<b> bold <i>text</i> </b>']
['<i>text</i>']
"""
locMarker = Empty().setParseAction(lambda s, loc, t: loc)
endlocMarker = locMarker.copy()
endlocMarker.callPreparse = False
matchExpr = locMarker("_original_start") + expr + endlocMarker("_original_end")
if asString:
extractText = lambda s, l, t: s[t._original_start: t._original_end]
else:
def extractText(s, l, t):
t[:] = [s[t.pop('_original_start'):t.pop('_original_end')]]
matchExpr.setParseAction(extractText)
matchExpr.ignoreExprs = expr.ignoreExprs
return matchExpr
def ungroup(expr):
"""Helper to undo pyparsing's default grouping of And expressions,
even if all but one are non-empty.
"""
return TokenConverter(expr).addParseAction(lambda t: t[0])
def locatedExpr(expr):
"""Helper to decorate a returned token with its starting and ending
locations in the input string.
This helper adds the following results names:
- locn_start = location where matched expression begins
- locn_end = location where matched expression ends
- value = the actual parsed results
Be careful if the input text contains ``<TAB>`` characters, you
may want to call :class:`ParserElement.parseWithTabs`
Example::
wd = Word(alphas)
for match in locatedExpr(wd).searchString("ljsdf123lksdjjf123lkkjj1222"):
print(match)
prints::
[[0, 'ljsdf', 5]]
[[8, 'lksdjjf', 15]]
[[18, 'lkkjj', 23]]
"""
locator = Empty().setParseAction(lambda s, l, t: l)
return Group(locator("locn_start") + expr("value") + locator.copy().leaveWhitespace()("locn_end"))
# convenience constants for positional expressions
empty = Empty().setName("empty")
lineStart = LineStart().setName("lineStart")
lineEnd = LineEnd().setName("lineEnd")
stringStart = StringStart().setName("stringStart")
stringEnd = StringEnd().setName("stringEnd")
_escapedPunc = Word(_bslash, r"\[]-*.$+^?()~ ", exact=2).setParseAction(lambda s, l, t: t[0][1])
_escapedHexChar = Regex(r"\\0?[xX][0-9a-fA-F]+").setParseAction(lambda s, l, t: unichr(int(t[0].lstrip(r'\0x'), 16)))
_escapedOctChar = Regex(r"\\0[0-7]+").setParseAction(lambda s, l, t: unichr(int(t[0][1:], 8)))
_singleChar = _escapedPunc | _escapedHexChar | _escapedOctChar | CharsNotIn(r'\]', exact=1)
_charRange = Group(_singleChar + Suppress("-") + _singleChar)
_reBracketExpr = Literal("[") + Optional("^").setResultsName("negate") + Group(OneOrMore(_charRange | _singleChar)).setResultsName("body") + "]"
def srange(s):
r"""Helper to easily define string ranges for use in Word
construction. Borrows syntax from regexp '[]' string range
definitions::
srange("[0-9]") -> "0123456789"
srange("[a-z]") -> "abcdefghijklmnopqrstuvwxyz"
srange("[a-z$_]") -> "abcdefghijklmnopqrstuvwxyz$_"
The input string must be enclosed in []'s, and the returned string
is the expanded character set joined into a single string. The
values enclosed in the []'s may be:
- a single character
- an escaped character with a leading backslash (such as ``\-``
or ``\]``)
- an escaped hex character with a leading ``'\x'``
(``\x21``, which is a ``'!'`` character) (``\0x##``
is also supported for backwards compatibility)
- an escaped octal character with a leading ``'\0'``
(``\041``, which is a ``'!'`` character)
- a range of any of the above, separated by a dash (``'a-z'``,
etc.)
- any combination of the above (``'aeiouy'``,
``'a-zA-Z0-9_$'``, etc.)
"""
_expanded = lambda p: p if not isinstance(p, ParseResults) else ''.join(unichr(c) for c in range(ord(p[0]), ord(p[1]) + 1))
try:
return "".join(_expanded(part) for part in _reBracketExpr.parseString(s).body)
except Exception:
return ""
def matchOnlyAtCol(n):
"""Helper method for defining parse actions that require matching at
a specific column in the input text.
"""
def verifyCol(strg, locn, toks):
if col(locn, strg) != n:
raise ParseException(strg, locn, "matched token not at column %d" % n)
return verifyCol
def replaceWith(replStr):
"""Helper method for common parse actions that simply return
a literal value. Especially useful when used with
:class:`transformString<ParserElement.transformString>` ().
Example::
num = Word(nums).setParseAction(lambda toks: int(toks[0]))
na = oneOf("N/A NA").setParseAction(replaceWith(math.nan))
term = na | num
OneOrMore(term).parseString("324 234 N/A 234") # -> [324, 234, nan, 234]
"""
return lambda s, l, t: [replStr]
def removeQuotes(s, l, t):
"""Helper parse action for removing quotation marks from parsed
quoted strings.
Example::
# by default, quotation marks are included in parsed results
quotedString.parseString("'Now is the Winter of our Discontent'") # -> ["'Now is the Winter of our Discontent'"]
# use removeQuotes to strip quotation marks from parsed results
quotedString.setParseAction(removeQuotes)
quotedString.parseString("'Now is the Winter of our Discontent'") # -> ["Now is the Winter of our Discontent"]
"""
return t[0][1:-1]
def tokenMap(func, *args):
"""Helper to define a parse action by mapping a function to all
elements of a ParseResults list. If any additional args are passed,
they are forwarded to the given function as additional arguments
after the token, as in
``hex_integer = Word(hexnums).setParseAction(tokenMap(int, 16))``,
which will convert the parsed data to an integer using base 16.
Example (compare the last to example in :class:`ParserElement.transformString`::
hex_ints = OneOrMore(Word(hexnums)).setParseAction(tokenMap(int, 16))
hex_ints.runTests('''
00 11 22 aa FF 0a 0d 1a
''')
upperword = Word(alphas).setParseAction(tokenMap(str.upper))
OneOrMore(upperword).runTests('''
my kingdom for a horse
''')
wd = Word(alphas).setParseAction(tokenMap(str.title))
OneOrMore(wd).setParseAction(' '.join).runTests('''
now is the winter of our discontent made glorious summer by this sun of york
''')
prints::
00 11 22 aa FF 0a 0d 1a
[0, 17, 34, 170, 255, 10, 13, 26]
my kingdom for a horse
['MY', 'KINGDOM', 'FOR', 'A', 'HORSE']
now is the winter of our discontent made glorious summer by this sun of york
['Now Is The Winter Of Our Discontent Made Glorious Summer By This Sun Of York']
"""
def pa(s, l, t):
return [func(tokn, *args) for tokn in t]
try:
func_name = getattr(func, '__name__',
getattr(func, '__class__').__name__)
except Exception:
func_name = str(func)
pa.__name__ = func_name
return pa
upcaseTokens = tokenMap(lambda t: _ustr(t).upper())
"""(Deprecated) Helper parse action to convert tokens to upper case.
Deprecated in favor of :class:`pyparsing_common.upcaseTokens`"""
downcaseTokens = tokenMap(lambda t: _ustr(t).lower())
"""(Deprecated) Helper parse action to convert tokens to lower case.
Deprecated in favor of :class:`pyparsing_common.downcaseTokens`"""
def _makeTags(tagStr, xml,
suppress_LT=Suppress("<"),
suppress_GT=Suppress(">")):
"""Internal helper to construct opening and closing tag expressions, given a tag name"""
if isinstance(tagStr, basestring):
resname = tagStr
tagStr = Keyword(tagStr, caseless=not xml)
else:
resname = tagStr.name
tagAttrName = Word(alphas, alphanums + "_-:")
if xml:
tagAttrValue = dblQuotedString.copy().setParseAction(removeQuotes)
openTag = (suppress_LT
+ tagStr("tag")
+ Dict(ZeroOrMore(Group(tagAttrName + Suppress("=") + tagAttrValue)))
+ Optional("/", default=[False])("empty").setParseAction(lambda s, l, t: t[0] == '/')
+ suppress_GT)
else:
tagAttrValue = quotedString.copy().setParseAction(removeQuotes) | Word(printables, excludeChars=">")
openTag = (suppress_LT
+ tagStr("tag")
+ Dict(ZeroOrMore(Group(tagAttrName.setParseAction(downcaseTokens)
+ Optional(Suppress("=") + tagAttrValue))))
+ Optional("/", default=[False])("empty").setParseAction(lambda s, l, t: t[0] == '/')
+ suppress_GT)
closeTag = Combine(_L("</") + tagStr + ">", adjacent=False)
openTag.setName("<%s>" % resname)
# add start<tagname> results name in parse action now that ungrouped names are not reported at two levels
openTag.addParseAction(lambda t: t.__setitem__("start" + "".join(resname.replace(":", " ").title().split()), t.copy()))
closeTag = closeTag("end" + "".join(resname.replace(":", " ").title().split())).setName("</%s>" % resname)
openTag.tag = resname
closeTag.tag = resname
openTag.tag_body = SkipTo(closeTag())
return openTag, closeTag
def makeHTMLTags(tagStr):
"""Helper to construct opening and closing tag expressions for HTML,
given a tag name. Matches tags in either upper or lower case,
attributes with namespaces and with quoted or unquoted values.
Example::
text = '<td>More info at the <a href="https://github.com/pyparsing/pyparsing/wiki">pyparsing</a> wiki page</td>'
# makeHTMLTags returns pyparsing expressions for the opening and
# closing tags as a 2-tuple
a, a_end = makeHTMLTags("A")
link_expr = a + SkipTo(a_end)("link_text") + a_end
for link in link_expr.searchString(text):
# attributes in the <A> tag (like "href" shown here) are
# also accessible as named results
print(link.link_text, '->', link.href)
prints::
pyparsing -> https://github.com/pyparsing/pyparsing/wiki
"""
return _makeTags(tagStr, False)
def makeXMLTags(tagStr):
"""Helper to construct opening and closing tag expressions for XML,
given a tag name. Matches tags only in the given upper/lower case.
Example: similar to :class:`makeHTMLTags`
"""
return _makeTags(tagStr, True)
def withAttribute(*args, **attrDict):
"""Helper to create a validating parse action to be used with start
tags created with :class:`makeXMLTags` or
:class:`makeHTMLTags`. Use ``withAttribute`` to qualify
a starting tag with a required attribute value, to avoid false
matches on common tags such as ``<TD>`` or ``<DIV>``.
Call ``withAttribute`` with a series of attribute names and
values. Specify the list of filter attributes names and values as:
- keyword arguments, as in ``(align="right")``, or
- as an explicit dict with ``**`` operator, when an attribute
name is also a Python reserved word, as in ``**{"class":"Customer", "align":"right"}``
- a list of name-value tuples, as in ``(("ns1:class", "Customer"), ("ns2:align", "right"))``
For attribute names with a namespace prefix, you must use the second
form. Attribute names are matched insensitive to upper/lower case.
If just testing for ``class`` (with or without a namespace), use
:class:`withClass`.
To verify that the attribute exists, but without specifying a value,
pass ``withAttribute.ANY_VALUE`` as the value.
Example::
html = '''
<div>
Some text
<div type="grid">1 4 0 1 0</div>
<div type="graph">1,3 2,3 1,1</div>
<div>this has no type</div>
</div>
'''
div,div_end = makeHTMLTags("div")
# only match div tag having a type attribute with value "grid"
div_grid = div().setParseAction(withAttribute(type="grid"))
grid_expr = div_grid + SkipTo(div | div_end)("body")
for grid_header in grid_expr.searchString(html):
print(grid_header.body)
# construct a match with any div tag having a type attribute, regardless of the value
div_any_type = div().setParseAction(withAttribute(type=withAttribute.ANY_VALUE))
div_expr = div_any_type + SkipTo(div | div_end)("body")
for div_header in div_expr.searchString(html):
print(div_header.body)
prints::
1 4 0 1 0
1 4 0 1 0
1,3 2,3 1,1
"""
if args:
attrs = args[:]
else:
attrs = attrDict.items()
attrs = [(k, v) for k, v in attrs]
def pa(s, l, tokens):
for attrName, attrValue in attrs:
if attrName not in tokens:
raise ParseException(s, l, "no matching attribute " + attrName)
if attrValue != withAttribute.ANY_VALUE and tokens[attrName] != attrValue:
raise ParseException(s, l, "attribute '%s' has value '%s', must be '%s'" %
(attrName, tokens[attrName], attrValue))
return pa
withAttribute.ANY_VALUE = object()
def withClass(classname, namespace=''):
"""Simplified version of :class:`withAttribute` when
matching on a div class - made difficult because ``class`` is
a reserved word in Python.
Example::
html = '''
<div>
Some text
<div class="grid">1 4 0 1 0</div>
<div class="graph">1,3 2,3 1,1</div>
<div>this &lt;div&gt; has no class</div>
</div>
'''
div,div_end = makeHTMLTags("div")
div_grid = div().setParseAction(withClass("grid"))
grid_expr = div_grid + SkipTo(div | div_end)("body")
for grid_header in grid_expr.searchString(html):
print(grid_header.body)
div_any_type = div().setParseAction(withClass(withAttribute.ANY_VALUE))
div_expr = div_any_type + SkipTo(div | div_end)("body")
for div_header in div_expr.searchString(html):
print(div_header.body)
prints::
1 4 0 1 0
1 4 0 1 0
1,3 2,3 1,1
"""
classattr = "%s:class" % namespace if namespace else "class"
return withAttribute(**{classattr: classname})
opAssoc = SimpleNamespace()
opAssoc.LEFT = object()
opAssoc.RIGHT = object()
def infixNotation(baseExpr, opList, lpar=Suppress('('), rpar=Suppress(')')):
"""Helper method for constructing grammars of expressions made up of
operators working in a precedence hierarchy. Operators may be unary
or binary, left- or right-associative. Parse actions can also be
attached to operator expressions. The generated parser will also
recognize the use of parentheses to override operator precedences
(see example below).
Note: if you define a deep operator list, you may see performance
issues when using infixNotation. See
:class:`ParserElement.enablePackrat` for a mechanism to potentially
improve your parser performance.
Parameters:
- baseExpr - expression representing the most basic element for the
nested
- opList - list of tuples, one for each operator precedence level
in the expression grammar; each tuple is of the form ``(opExpr,
numTerms, rightLeftAssoc, parseAction)``, where:
- opExpr is the pyparsing expression for the operator; may also
be a string, which will be converted to a Literal; if numTerms
is 3, opExpr is a tuple of two expressions, for the two
operators separating the 3 terms
- numTerms is the number of terms for this operator (must be 1,
2, or 3)
- rightLeftAssoc is the indicator whether the operator is right
or left associative, using the pyparsing-defined constants
``opAssoc.RIGHT`` and ``opAssoc.LEFT``.
- parseAction is the parse action to be associated with
expressions matching this operator expression (the parse action
tuple member may be omitted); if the parse action is passed
a tuple or list of functions, this is equivalent to calling
``setParseAction(*fn)``
(:class:`ParserElement.setParseAction`)
- lpar - expression for matching left-parentheses
(default= ``Suppress('(')``)
- rpar - expression for matching right-parentheses
(default= ``Suppress(')')``)
Example::
# simple example of four-function arithmetic with ints and
# variable names
integer = pyparsing_common.signed_integer
varname = pyparsing_common.identifier
arith_expr = infixNotation(integer | varname,
[
('-', 1, opAssoc.RIGHT),
(oneOf('* /'), 2, opAssoc.LEFT),
(oneOf('+ -'), 2, opAssoc.LEFT),
])
arith_expr.runTests('''
5+3*6
(5+3)*6
-2--11
''', fullDump=False)
prints::
5+3*6
[[5, '+', [3, '*', 6]]]
(5+3)*6
[[[5, '+', 3], '*', 6]]
-2--11
[[['-', 2], '-', ['-', 11]]]
"""
# captive version of FollowedBy that does not do parse actions or capture results names
class _FB(FollowedBy):
def parseImpl(self, instring, loc, doActions=True):
self.expr.tryParse(instring, loc)
return loc, []
ret = Forward()
lastExpr = baseExpr | (lpar + ret + rpar)
for i, operDef in enumerate(opList):
opExpr, arity, rightLeftAssoc, pa = (operDef + (None, ))[:4]
termName = "%s term" % opExpr if arity < 3 else "%s%s term" % opExpr
if arity == 3:
if opExpr is None or len(opExpr) != 2:
raise ValueError(
"if numterms=3, opExpr must be a tuple or list of two expressions")
opExpr1, opExpr2 = opExpr
thisExpr = Forward().setName(termName)
if rightLeftAssoc == opAssoc.LEFT:
if arity == 1:
matchExpr = _FB(lastExpr + opExpr) + Group(lastExpr + OneOrMore(opExpr))
elif arity == 2:
if opExpr is not None:
matchExpr = _FB(lastExpr + opExpr + lastExpr) + Group(lastExpr + OneOrMore(opExpr + lastExpr))
else:
matchExpr = _FB(lastExpr + lastExpr) + Group(lastExpr + OneOrMore(lastExpr))
elif arity == 3:
matchExpr = (_FB(lastExpr + opExpr1 + lastExpr + opExpr2 + lastExpr)
+ Group(lastExpr + OneOrMore(opExpr1 + lastExpr + opExpr2 + lastExpr)))
else:
raise ValueError("operator must be unary (1), binary (2), or ternary (3)")
elif rightLeftAssoc == opAssoc.RIGHT:
if arity == 1:
# try to avoid LR with this extra test
if not isinstance(opExpr, Optional):
opExpr = Optional(opExpr)
matchExpr = _FB(opExpr.expr + thisExpr) + Group(opExpr + thisExpr)
elif arity == 2:
if opExpr is not None:
matchExpr = _FB(lastExpr + opExpr + thisExpr) + Group(lastExpr + OneOrMore(opExpr + thisExpr))
else:
matchExpr = _FB(lastExpr + thisExpr) + Group(lastExpr + OneOrMore(thisExpr))
elif arity == 3:
matchExpr = (_FB(lastExpr + opExpr1 + thisExpr + opExpr2 + thisExpr)
+ Group(lastExpr + opExpr1 + thisExpr + opExpr2 + thisExpr))
else:
raise ValueError("operator must be unary (1), binary (2), or ternary (3)")
else:
raise ValueError("operator must indicate right or left associativity")
if pa:
if isinstance(pa, (tuple, list)):
matchExpr.setParseAction(*pa)
else:
matchExpr.setParseAction(pa)
thisExpr <<= (matchExpr.setName(termName) | lastExpr)
lastExpr = thisExpr
ret <<= lastExpr
return ret
operatorPrecedence = infixNotation
"""(Deprecated) Former name of :class:`infixNotation`, will be
dropped in a future release."""
dblQuotedString = Combine(Regex(r'"(?:[^"\n\r\\]|(?:"")|(?:\\(?:[^x]|x[0-9a-fA-F]+)))*') + '"').setName("string enclosed in double quotes")
sglQuotedString = Combine(Regex(r"'(?:[^'\n\r\\]|(?:'')|(?:\\(?:[^x]|x[0-9a-fA-F]+)))*") + "'").setName("string enclosed in single quotes")
quotedString = Combine(Regex(r'"(?:[^"\n\r\\]|(?:"")|(?:\\(?:[^x]|x[0-9a-fA-F]+)))*') + '"'
| Regex(r"'(?:[^'\n\r\\]|(?:'')|(?:\\(?:[^x]|x[0-9a-fA-F]+)))*") + "'").setName("quotedString using single or double quotes")
unicodeString = Combine(_L('u') + quotedString.copy()).setName("unicode string literal")
def nestedExpr(opener="(", closer=")", content=None, ignoreExpr=quotedString.copy()):
"""Helper method for defining nested lists enclosed in opening and
closing delimiters ("(" and ")" are the default).
Parameters:
- opener - opening character for a nested list
(default= ``"("``); can also be a pyparsing expression
- closer - closing character for a nested list
(default= ``")"``); can also be a pyparsing expression
- content - expression for items within the nested lists
(default= ``None``)
- ignoreExpr - expression for ignoring opening and closing
delimiters (default= :class:`quotedString`)
If an expression is not provided for the content argument, the
nested expression will capture all whitespace-delimited content
between delimiters as a list of separate values.
Use the ``ignoreExpr`` argument to define expressions that may
contain opening or closing characters that should not be treated as
opening or closing characters for nesting, such as quotedString or
a comment expression. Specify multiple expressions using an
:class:`Or` or :class:`MatchFirst`. The default is
:class:`quotedString`, but if no expressions are to be ignored, then
pass ``None`` for this argument.
Example::
data_type = oneOf("void int short long char float double")
decl_data_type = Combine(data_type + Optional(Word('*')))
ident = Word(alphas+'_', alphanums+'_')
number = pyparsing_common.number
arg = Group(decl_data_type + ident)
LPAR, RPAR = map(Suppress, "()")
code_body = nestedExpr('{', '}', ignoreExpr=(quotedString | cStyleComment))
c_function = (decl_data_type("type")
+ ident("name")
+ LPAR + Optional(delimitedList(arg), [])("args") + RPAR
+ code_body("body"))
c_function.ignore(cStyleComment)
source_code = '''
int is_odd(int x) {
return (x%2);
}
int dec_to_hex(char hchar) {
if (hchar >= '0' && hchar <= '9') {
return (ord(hchar)-ord('0'));
} else {
return (10+ord(hchar)-ord('A'));
}
}
'''
for func in c_function.searchString(source_code):
print("%(name)s (%(type)s) args: %(args)s" % func)
prints::
is_odd (int) args: [['int', 'x']]
dec_to_hex (int) args: [['char', 'hchar']]
"""
if opener == closer:
raise ValueError("opening and closing strings cannot be the same")
if content is None:
if isinstance(opener, basestring) and isinstance(closer, basestring):
if len(opener) == 1 and len(closer) == 1:
if ignoreExpr is not None:
content = (Combine(OneOrMore(~ignoreExpr
+ CharsNotIn(opener
+ closer
+ ParserElement.DEFAULT_WHITE_CHARS, exact=1)
)
).setParseAction(lambda t: t[0].strip()))
else:
content = (empty.copy() + CharsNotIn(opener
+ closer
+ ParserElement.DEFAULT_WHITE_CHARS
).setParseAction(lambda t: t[0].strip()))
else:
if ignoreExpr is not None:
content = (Combine(OneOrMore(~ignoreExpr
+ ~Literal(opener)
+ ~Literal(closer)
+ CharsNotIn(ParserElement.DEFAULT_WHITE_CHARS, exact=1))
).setParseAction(lambda t: t[0].strip()))
else:
content = (Combine(OneOrMore(~Literal(opener)
+ ~Literal(closer)
+ CharsNotIn(ParserElement.DEFAULT_WHITE_CHARS, exact=1))
).setParseAction(lambda t: t[0].strip()))
else:
raise ValueError("opening and closing arguments must be strings if no content expression is given")
ret = Forward()
if ignoreExpr is not None:
ret <<= Group(Suppress(opener) + ZeroOrMore(ignoreExpr | ret | content) + Suppress(closer))
else:
ret <<= Group(Suppress(opener) + ZeroOrMore(ret | content) + Suppress(closer))
ret.setName('nested %s%s expression' % (opener, closer))
return ret
def indentedBlock(blockStatementExpr, indentStack, indent=True):
"""Helper method for defining space-delimited indentation blocks,
such as those used to define block statements in Python source code.
Parameters:
- blockStatementExpr - expression defining syntax of statement that
is repeated within the indented block
- indentStack - list created by caller to manage indentation stack
(multiple statementWithIndentedBlock expressions within a single
grammar should share a common indentStack)
- indent - boolean indicating whether block must be indented beyond
the current level; set to False for block of left-most
statements (default= ``True``)
A valid block must contain at least one ``blockStatement``.
Example::
data = '''
def A(z):
A1
B = 100
G = A2
A2
A3
B
def BB(a,b,c):
BB1
def BBA():
bba1
bba2
bba3
C
D
def spam(x,y):
def eggs(z):
pass
'''
indentStack = [1]
stmt = Forward()
identifier = Word(alphas, alphanums)
funcDecl = ("def" + identifier + Group("(" + Optional(delimitedList(identifier)) + ")") + ":")
func_body = indentedBlock(stmt, indentStack)
funcDef = Group(funcDecl + func_body)
rvalue = Forward()
funcCall = Group(identifier + "(" + Optional(delimitedList(rvalue)) + ")")
rvalue << (funcCall | identifier | Word(nums))
assignment = Group(identifier + "=" + rvalue)
stmt << (funcDef | assignment | identifier)
module_body = OneOrMore(stmt)
parseTree = module_body.parseString(data)
parseTree.pprint()
prints::
[['def',
'A',
['(', 'z', ')'],
':',
[['A1'], [['B', '=', '100']], [['G', '=', 'A2']], ['A2'], ['A3']]],
'B',
['def',
'BB',
['(', 'a', 'b', 'c', ')'],
':',
[['BB1'], [['def', 'BBA', ['(', ')'], ':', [['bba1'], ['bba2'], ['bba3']]]]]],
'C',
'D',
['def',
'spam',
['(', 'x', 'y', ')'],
':',
[[['def', 'eggs', ['(', 'z', ')'], ':', [['pass']]]]]]]
"""
backup_stack = indentStack[:]
def reset_stack():
indentStack[:] = backup_stack
def checkPeerIndent(s, l, t):
if l >= len(s): return
curCol = col(l, s)
if curCol != indentStack[-1]:
if curCol > indentStack[-1]:
raise ParseException(s, l, "illegal nesting")
raise ParseException(s, l, "not a peer entry")
def checkSubIndent(s, l, t):
curCol = col(l, s)
if curCol > indentStack[-1]:
indentStack.append(curCol)
else:
raise ParseException(s, l, "not a subentry")
def checkUnindent(s, l, t):
if l >= len(s): return
curCol = col(l, s)
if not(indentStack and curCol in indentStack):
raise ParseException(s, l, "not an unindent")
if curCol < indentStack[-1]:
indentStack.pop()
NL = OneOrMore(LineEnd().setWhitespaceChars("\t ").suppress(), stopOn=StringEnd())
INDENT = (Empty() + Empty().setParseAction(checkSubIndent)).setName('INDENT')
PEER = Empty().setParseAction(checkPeerIndent).setName('')
UNDENT = Empty().setParseAction(checkUnindent).setName('UNINDENT')
if indent:
smExpr = Group(Optional(NL)
+ INDENT
+ OneOrMore(PEER + Group(blockStatementExpr) + Optional(NL), stopOn=StringEnd())
+ UNDENT)
else:
smExpr = Group(Optional(NL)
+ OneOrMore(PEER + Group(blockStatementExpr) + Optional(NL), stopOn=StringEnd())
+ UNDENT)
smExpr.setFailAction(lambda a, b, c, d: reset_stack())
blockStatementExpr.ignore(_bslash + LineEnd())
return smExpr.setName('indented block')
alphas8bit = srange(r"[\0xc0-\0xd6\0xd8-\0xf6\0xf8-\0xff]")
punc8bit = srange(r"[\0xa1-\0xbf\0xd7\0xf7]")
anyOpenTag, anyCloseTag = makeHTMLTags(Word(alphas, alphanums + "_:").setName('any tag'))
_htmlEntityMap = dict(zip("gt lt amp nbsp quot apos".split(), '><& "\''))
commonHTMLEntity = Regex('&(?P<entity>' + '|'.join(_htmlEntityMap.keys()) +");").setName("common HTML entity")
def replaceHTMLEntity(t):
"""Helper parser action to replace common HTML entities with their special characters"""
return _htmlEntityMap.get(t.entity)
# it's easy to get these comment structures wrong - they're very common, so may as well make them available
cStyleComment = Combine(Regex(r"/\*(?:[^*]|\*(?!/))*") + '*/').setName("C style comment")
"Comment of the form ``/* ... */``"
htmlComment = Regex(r"<!--[\s\S]*?-->").setName("HTML comment")
"Comment of the form ``<!-- ... -->``"
restOfLine = Regex(r".*").leaveWhitespace().setName("rest of line")
dblSlashComment = Regex(r"//(?:\\\n|[^\n])*").setName("// comment")
"Comment of the form ``// ... (to end of line)``"
cppStyleComment = Combine(Regex(r"/\*(?:[^*]|\*(?!/))*") + '*/' | dblSlashComment).setName("C++ style comment")
"Comment of either form :class:`cStyleComment` or :class:`dblSlashComment`"
javaStyleComment = cppStyleComment
"Same as :class:`cppStyleComment`"
pythonStyleComment = Regex(r"#.*").setName("Python style comment")
"Comment of the form ``# ... (to end of line)``"
_commasepitem = Combine(OneOrMore(Word(printables, excludeChars=',')
+ Optional(Word(" \t")
+ ~Literal(",") + ~LineEnd()))).streamline().setName("commaItem")
commaSeparatedList = delimitedList(Optional(quotedString.copy() | _commasepitem, default="")).setName("commaSeparatedList")
"""(Deprecated) Predefined expression of 1 or more printable words or
quoted strings, separated by commas.
This expression is deprecated in favor of :class:`pyparsing_common.comma_separated_list`.
"""
# some other useful expressions - using lower-case class name since we are really using this as a namespace
class pyparsing_common:
"""Here are some common low-level expressions that may be useful in
jump-starting parser development:
- numeric forms (:class:`integers<integer>`, :class:`reals<real>`,
:class:`scientific notation<sci_real>`)
- common :class:`programming identifiers<identifier>`
- network addresses (:class:`MAC<mac_address>`,
:class:`IPv4<ipv4_address>`, :class:`IPv6<ipv6_address>`)
- ISO8601 :class:`dates<iso8601_date>` and
:class:`datetime<iso8601_datetime>`
- :class:`UUID<uuid>`
- :class:`comma-separated list<comma_separated_list>`
Parse actions:
- :class:`convertToInteger`
- :class:`convertToFloat`
- :class:`convertToDate`
- :class:`convertToDatetime`
- :class:`stripHTMLTags`
- :class:`upcaseTokens`
- :class:`downcaseTokens`
Example::
pyparsing_common.number.runTests('''
# any int or real number, returned as the appropriate type
100
-100
+100
3.14159
6.02e23
1e-12
''')
pyparsing_common.fnumber.runTests('''
# any int or real number, returned as float
100
-100
+100
3.14159
6.02e23
1e-12
''')
pyparsing_common.hex_integer.runTests('''
# hex numbers
100
FF
''')
pyparsing_common.fraction.runTests('''
# fractions
1/2
-3/4
''')
pyparsing_common.mixed_integer.runTests('''
# mixed fractions
1
1/2
-3/4
1-3/4
''')
import uuid
pyparsing_common.uuid.setParseAction(tokenMap(uuid.UUID))
pyparsing_common.uuid.runTests('''
# uuid
12345678-1234-5678-1234-567812345678
''')
prints::
# any int or real number, returned as the appropriate type
100
[100]
-100
[-100]
+100
[100]
3.14159
[3.14159]
6.02e23
[6.02e+23]
1e-12
[1e-12]
# any int or real number, returned as float
100
[100.0]
-100
[-100.0]
+100
[100.0]
3.14159
[3.14159]
6.02e23
[6.02e+23]
1e-12
[1e-12]
# hex numbers
100
[256]
FF
[255]
# fractions
1/2
[0.5]
-3/4
[-0.75]
# mixed fractions
1
[1]
1/2
[0.5]
-3/4
[-0.75]
1-3/4
[1.75]
# uuid
12345678-1234-5678-1234-567812345678
[UUID('12345678-1234-5678-1234-567812345678')]
"""
convertToInteger = tokenMap(int)
"""
Parse action for converting parsed integers to Python int
"""
convertToFloat = tokenMap(float)
"""
Parse action for converting parsed numbers to Python float
"""
integer = Word(nums).setName("integer").setParseAction(convertToInteger)
"""expression that parses an unsigned integer, returns an int"""
hex_integer = Word(hexnums).setName("hex integer").setParseAction(tokenMap(int, 16))
"""expression that parses a hexadecimal integer, returns an int"""
signed_integer = Regex(r'[+-]?\d+').setName("signed integer").setParseAction(convertToInteger)
"""expression that parses an integer with optional leading sign, returns an int"""
fraction = (signed_integer().setParseAction(convertToFloat) + '/' + signed_integer().setParseAction(convertToFloat)).setName("fraction")
"""fractional expression of an integer divided by an integer, returns a float"""
fraction.addParseAction(lambda t: t[0]/t[-1])
mixed_integer = (fraction | signed_integer + Optional(Optional('-').suppress() + fraction)).setName("fraction or mixed integer-fraction")
"""mixed integer of the form 'integer - fraction', with optional leading integer, returns float"""
mixed_integer.addParseAction(sum)
real = Regex(r'[+-]?(?:\d+\.\d*|\.\d+)').setName("real number").setParseAction(convertToFloat)
"""expression that parses a floating point number and returns a float"""
sci_real = Regex(r'[+-]?(?:\d+(?:[eE][+-]?\d+)|(?:\d+\.\d*|\.\d+)(?:[eE][+-]?\d+)?)').setName("real number with scientific notation").setParseAction(convertToFloat)
"""expression that parses a floating point number with optional
scientific notation and returns a float"""
# streamlining this expression makes the docs nicer-looking
number = (sci_real | real | signed_integer).streamline()
"""any numeric expression, returns the corresponding Python type"""
fnumber = Regex(r'[+-]?\d+\.?\d*([eE][+-]?\d+)?').setName("fnumber").setParseAction(convertToFloat)
"""any int or real number, returned as float"""
identifier = Word(alphas + '_', alphanums + '_').setName("identifier")
"""typical code identifier (leading alpha or '_', followed by 0 or more alphas, nums, or '_')"""
ipv4_address = Regex(r'(25[0-5]|2[0-4][0-9]|1?[0-9]{1,2})(\.(25[0-5]|2[0-4][0-9]|1?[0-9]{1,2})){3}').setName("IPv4 address")
"IPv4 address (``0.0.0.0 - 255.255.255.255``)"
_ipv6_part = Regex(r'[0-9a-fA-F]{1,4}').setName("hex_integer")
_full_ipv6_address = (_ipv6_part + (':' + _ipv6_part) * 7).setName("full IPv6 address")
_short_ipv6_address = (Optional(_ipv6_part + (':' + _ipv6_part) * (0, 6))
+ "::"
+ Optional(_ipv6_part + (':' + _ipv6_part) * (0, 6))
).setName("short IPv6 address")
_short_ipv6_address.addCondition(lambda t: sum(1 for tt in t if pyparsing_common._ipv6_part.matches(tt)) < 8)
_mixed_ipv6_address = ("::ffff:" + ipv4_address).setName("mixed IPv6 address")
ipv6_address = Combine((_full_ipv6_address | _mixed_ipv6_address | _short_ipv6_address).setName("IPv6 address")).setName("IPv6 address")
"IPv6 address (long, short, or mixed form)"
mac_address = Regex(r'[0-9a-fA-F]{2}([:.-])[0-9a-fA-F]{2}(?:\1[0-9a-fA-F]{2}){4}').setName("MAC address")
"MAC address xx:xx:xx:xx:xx (may also have '-' or '.' delimiters)"
@staticmethod
def convertToDate(fmt="%Y-%m-%d"):
"""
Helper to create a parse action for converting parsed date string to Python datetime.date
Params -
- fmt - format to be passed to datetime.strptime (default= ``"%Y-%m-%d"``)
Example::
date_expr = pyparsing_common.iso8601_date.copy()
date_expr.setParseAction(pyparsing_common.convertToDate())
print(date_expr.parseString("1999-12-31"))
prints::
[datetime.date(1999, 12, 31)]
"""
def cvt_fn(s, l, t):
try:
return datetime.strptime(t[0], fmt).date()
except ValueError as ve:
raise ParseException(s, l, str(ve))
return cvt_fn
@staticmethod
def convertToDatetime(fmt="%Y-%m-%dT%H:%M:%S.%f"):
"""Helper to create a parse action for converting parsed
datetime string to Python datetime.datetime
Params -
- fmt - format to be passed to datetime.strptime (default= ``"%Y-%m-%dT%H:%M:%S.%f"``)
Example::
dt_expr = pyparsing_common.iso8601_datetime.copy()
dt_expr.setParseAction(pyparsing_common.convertToDatetime())
print(dt_expr.parseString("1999-12-31T23:59:59.999"))
prints::
[datetime.datetime(1999, 12, 31, 23, 59, 59, 999000)]
"""
def cvt_fn(s, l, t):
try:
return datetime.strptime(t[0], fmt)
except ValueError as ve:
raise ParseException(s, l, str(ve))
return cvt_fn
iso8601_date = Regex(r'(?P<year>\d{4})(?:-(?P<month>\d\d)(?:-(?P<day>\d\d))?)?').setName("ISO8601 date")
"ISO8601 date (``yyyy-mm-dd``)"
iso8601_datetime = Regex(r'(?P<year>\d{4})-(?P<month>\d\d)-(?P<day>\d\d)[T ](?P<hour>\d\d):(?P<minute>\d\d)(:(?P<second>\d\d(\.\d*)?)?)?(?P<tz>Z|[+-]\d\d:?\d\d)?').setName("ISO8601 datetime")
"ISO8601 datetime (``yyyy-mm-ddThh:mm:ss.s(Z|+-00:00)``) - trailing seconds, milliseconds, and timezone optional; accepts separating ``'T'`` or ``' '``"
uuid = Regex(r'[0-9a-fA-F]{8}(-[0-9a-fA-F]{4}){3}-[0-9a-fA-F]{12}').setName("UUID")
"UUID (``xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx``)"
_html_stripper = anyOpenTag.suppress() | anyCloseTag.suppress()
@staticmethod
def stripHTMLTags(s, l, tokens):
"""Parse action to remove HTML tags from web page HTML source
Example::
# strip HTML links from normal text
text = '<td>More info at the <a href="https://github.com/pyparsing/pyparsing/wiki">pyparsing</a> wiki page</td>'
td, td_end = makeHTMLTags("TD")
table_text = td + SkipTo(td_end).setParseAction(pyparsing_common.stripHTMLTags)("body") + td_end
print(table_text.parseString(text).body)
Prints::
More info at the pyparsing wiki page
"""
return pyparsing_common._html_stripper.transformString(tokens[0])
_commasepitem = Combine(OneOrMore(~Literal(",")
+ ~LineEnd()
+ Word(printables, excludeChars=',')
+ Optional(White(" \t")))).streamline().setName("commaItem")
comma_separated_list = delimitedList(Optional(quotedString.copy()
| _commasepitem, default='')
).setName("comma separated list")
"""Predefined expression of 1 or more printable words or quoted strings, separated by commas."""
upcaseTokens = staticmethod(tokenMap(lambda t: _ustr(t).upper()))
"""Parse action to convert tokens to upper case."""
downcaseTokens = staticmethod(tokenMap(lambda t: _ustr(t).lower()))
"""Parse action to convert tokens to lower case."""
class _lazyclassproperty(object):
def __init__(self, fn):
self.fn = fn
self.__doc__ = fn.__doc__
self.__name__ = fn.__name__
def __get__(self, obj, cls):
if cls is None:
cls = type(obj)
if not hasattr(cls, '_intern') or any(cls._intern is getattr(superclass, '_intern', [])
for superclass in cls.__mro__[1:]):
cls._intern = {}
attrname = self.fn.__name__
if attrname not in cls._intern:
cls._intern[attrname] = self.fn(cls)
return cls._intern[attrname]
class unicode_set(object):
"""
A set of Unicode characters, for language-specific strings for
``alphas``, ``nums``, ``alphanums``, and ``printables``.
A unicode_set is defined by a list of ranges in the Unicode character
set, in a class attribute ``_ranges``, such as::
_ranges = [(0x0020, 0x007e), (0x00a0, 0x00ff),]
A unicode set can also be defined using multiple inheritance of other unicode sets::
class CJK(Chinese, Japanese, Korean):
pass
"""
_ranges = []
@classmethod
def _get_chars_for_ranges(cls):
ret = []
for cc in cls.__mro__:
if cc is unicode_set:
break
for rr in cc._ranges:
ret.extend(range(rr[0], rr[-1] + 1))
return [unichr(c) for c in sorted(set(ret))]
@_lazyclassproperty
def printables(cls):
"all non-whitespace characters in this range"
return u''.join(filterfalse(unicode.isspace, cls._get_chars_for_ranges()))
@_lazyclassproperty
def alphas(cls):
"all alphabetic characters in this range"
return u''.join(filter(unicode.isalpha, cls._get_chars_for_ranges()))
@_lazyclassproperty
def nums(cls):
"all numeric digit characters in this range"
return u''.join(filter(unicode.isdigit, cls._get_chars_for_ranges()))
@_lazyclassproperty
def alphanums(cls):
"all alphanumeric characters in this range"
return cls.alphas + cls.nums
class pyparsing_unicode(unicode_set):
"""
A namespace class for defining common language unicode_sets.
"""
_ranges = [(32, sys.maxunicode)]
class Latin1(unicode_set):
"Unicode set for Latin-1 Unicode Character Range"
_ranges = [(0x0020, 0x007e), (0x00a0, 0x00ff),]
class LatinA(unicode_set):
"Unicode set for Latin-A Unicode Character Range"
_ranges = [(0x0100, 0x017f),]
class LatinB(unicode_set):
"Unicode set for Latin-B Unicode Character Range"
_ranges = [(0x0180, 0x024f),]
class Greek(unicode_set):
"Unicode set for Greek Unicode Character Ranges"
_ranges = [
(0x0370, 0x03ff), (0x1f00, 0x1f15), (0x1f18, 0x1f1d), (0x1f20, 0x1f45), (0x1f48, 0x1f4d),
(0x1f50, 0x1f57), (0x1f59,), (0x1f5b,), (0x1f5d,), (0x1f5f, 0x1f7d), (0x1f80, 0x1fb4), (0x1fb6, 0x1fc4),
(0x1fc6, 0x1fd3), (0x1fd6, 0x1fdb), (0x1fdd, 0x1fef), (0x1ff2, 0x1ff4), (0x1ff6, 0x1ffe),
]
class Cyrillic(unicode_set):
"Unicode set for Cyrillic Unicode Character Range"
_ranges = [(0x0400, 0x04ff)]
class Chinese(unicode_set):
"Unicode set for Chinese Unicode Character Range"
_ranges = [(0x4e00, 0x9fff), (0x3000, 0x303f),]
class Japanese(unicode_set):
"Unicode set for Japanese Unicode Character Range, combining Kanji, Hiragana, and Katakana ranges"
_ranges = []
class Kanji(unicode_set):
"Unicode set for Kanji Unicode Character Range"
_ranges = [(0x4E00, 0x9Fbf), (0x3000, 0x303f),]
class Hiragana(unicode_set):
"Unicode set for Hiragana Unicode Character Range"
_ranges = [(0x3040, 0x309f),]
class Katakana(unicode_set):
"Unicode set for Katakana Unicode Character Range"
_ranges = [(0x30a0, 0x30ff),]
class Korean(unicode_set):
"Unicode set for Korean Unicode Character Range"
_ranges = [(0xac00, 0xd7af), (0x1100, 0x11ff), (0x3130, 0x318f), (0xa960, 0xa97f), (0xd7b0, 0xd7ff), (0x3000, 0x303f),]
class CJK(Chinese, Japanese, Korean):
"Unicode set for combined Chinese, Japanese, and Korean (CJK) Unicode Character Range"
pass
class Thai(unicode_set):
"Unicode set for Thai Unicode Character Range"
_ranges = [(0x0e01, 0x0e3a), (0x0e3f, 0x0e5b),]
class Arabic(unicode_set):
"Unicode set for Arabic Unicode Character Range"
_ranges = [(0x0600, 0x061b), (0x061e, 0x06ff), (0x0700, 0x077f),]
class Hebrew(unicode_set):
"Unicode set for Hebrew Unicode Character Range"
_ranges = [(0x0590, 0x05ff),]
class Devanagari(unicode_set):
"Unicode set for Devanagari Unicode Character Range"
_ranges = [(0x0900, 0x097f), (0xa8e0, 0xa8ff)]
pyparsing_unicode.Japanese._ranges = (pyparsing_unicode.Japanese.Kanji._ranges
+ pyparsing_unicode.Japanese.Hiragana._ranges
+ pyparsing_unicode.Japanese.Katakana._ranges)
# define ranges in language character sets
if PY_3:
setattr(pyparsing_unicode, u"العربية", pyparsing_unicode.Arabic)
setattr(pyparsing_unicode, u"中文", pyparsing_unicode.Chinese)
setattr(pyparsing_unicode, u"кириллица", pyparsing_unicode.Cyrillic)
setattr(pyparsing_unicode, u"Ελληνικά", pyparsing_unicode.Greek)
setattr(pyparsing_unicode, u"עִברִית", pyparsing_unicode.Hebrew)
setattr(pyparsing_unicode, u"日本語", pyparsing_unicode.Japanese)
setattr(pyparsing_unicode.Japanese, u"漢字", pyparsing_unicode.Japanese.Kanji)
setattr(pyparsing_unicode.Japanese, u"カタカナ", pyparsing_unicode.Japanese.Katakana)
setattr(pyparsing_unicode.Japanese, u"ひらがな", pyparsing_unicode.Japanese.Hiragana)
setattr(pyparsing_unicode, u"한국어", pyparsing_unicode.Korean)
setattr(pyparsing_unicode, u"ไทย", pyparsing_unicode.Thai)
setattr(pyparsing_unicode, u"देवनागरी", pyparsing_unicode.Devanagari)
class pyparsing_test:
"""
namespace class for classes useful in writing unit tests
"""
class reset_pyparsing_context:
"""
Context manager to be used when writing unit tests that modify pyparsing config values:
- packrat parsing
- default whitespace characters.
- default keyword characters
- literal string auto-conversion class
- __diag__ settings
Example:
with reset_pyparsing_context():
# test that literals used to construct a grammar are automatically suppressed
ParserElement.inlineLiteralsUsing(Suppress)
term = Word(alphas) | Word(nums)
group = Group('(' + term[...] + ')')
# assert that the '()' characters are not included in the parsed tokens
self.assertParseAndCheckLisst(group, "(abc 123 def)", ['abc', '123', 'def'])
# after exiting context manager, literals are converted to Literal expressions again
"""
def __init__(self):
self._save_context = {}
def save(self):
self._save_context["default_whitespace"] = ParserElement.DEFAULT_WHITE_CHARS
self._save_context["default_keyword_chars"] = Keyword.DEFAULT_KEYWORD_CHARS
self._save_context[
"literal_string_class"
] = ParserElement._literalStringClass
self._save_context["packrat_enabled"] = ParserElement._packratEnabled
self._save_context["packrat_parse"] = ParserElement._parse
self._save_context["__diag__"] = {
name: getattr(__diag__, name) for name in __diag__._all_names
}
self._save_context["__compat__"] = {
"collect_all_And_tokens": __compat__.collect_all_And_tokens
}
return self
def restore(self):
# reset pyparsing global state
if (
ParserElement.DEFAULT_WHITE_CHARS
!= self._save_context["default_whitespace"]
):
ParserElement.setDefaultWhitespaceChars(
self._save_context["default_whitespace"]
)
Keyword.DEFAULT_KEYWORD_CHARS = self._save_context["default_keyword_chars"]
ParserElement.inlineLiteralsUsing(
self._save_context["literal_string_class"]
)
for name, value in self._save_context["__diag__"].items():
setattr(__diag__, name, value)
ParserElement._packratEnabled = self._save_context["packrat_enabled"]
ParserElement._parse = self._save_context["packrat_parse"]
__compat__.collect_all_And_tokens = self._save_context["__compat__"]
def __enter__(self):
return self.save()
def __exit__(self, *args):
return self.restore()
class TestParseResultsAsserts:
"""
A mixin class to add parse results assertion methods to normal unittest.TestCase classes.
"""
def assertParseResultsEquals(
self, result, expected_list=None, expected_dict=None, msg=None
):
"""
Unit test assertion to compare a ParseResults object with an optional expected_list,
and compare any defined results names with an optional expected_dict.
"""
if expected_list is not None:
self.assertEqual(expected_list, result.asList(), msg=msg)
if expected_dict is not None:
self.assertEqual(expected_dict, result.asDict(), msg=msg)
def assertParseAndCheckList(
self, expr, test_string, expected_list, msg=None, verbose=True
):
"""
Convenience wrapper assert to test a parser element and input string, and assert that
the resulting ParseResults.asList() is equal to the expected_list.
"""
result = expr.parseString(test_string, parseAll=True)
if verbose:
print(result.dump())
self.assertParseResultsEquals(result, expected_list=expected_list, msg=msg)
def assertParseAndCheckDict(
self, expr, test_string, expected_dict, msg=None, verbose=True
):
"""
Convenience wrapper assert to test a parser element and input string, and assert that
the resulting ParseResults.asDict() is equal to the expected_dict.
"""
result = expr.parseString(test_string, parseAll=True)
if verbose:
print(result.dump())
self.assertParseResultsEquals(result, expected_dict=expected_dict, msg=msg)
def assertRunTestResults(
self, run_tests_report, expected_parse_results=None, msg=None
):
"""
Unit test assertion to evaluate output of ParserElement.runTests(). If a list of
list-dict tuples is given as the expected_parse_results argument, then these are zipped
with the report tuples returned by runTests and evaluated using assertParseResultsEquals.
Finally, asserts that the overall runTests() success value is True.
:param run_tests_report: tuple(bool, [tuple(str, ParseResults or Exception)]) returned from runTests
:param expected_parse_results (optional): [tuple(str, list, dict, Exception)]
"""
run_test_success, run_test_results = run_tests_report
if expected_parse_results is not None:
merged = [
(rpt[0], rpt[1], expected)
for rpt, expected in zip(run_test_results, expected_parse_results)
]
for test_string, result, expected in merged:
# expected should be a tuple containing a list and/or a dict or an exception,
# and optional failure message string
# an empty tuple will skip any result validation
fail_msg = next(
(exp for exp in expected if isinstance(exp, str)), None
)
expected_exception = next(
(
exp
for exp in expected
if isinstance(exp, type) and issubclass(exp, Exception)
),
None,
)
if expected_exception is not None:
with self.assertRaises(
expected_exception=expected_exception, msg=fail_msg or msg
):
if isinstance(result, Exception):
raise result
else:
expected_list = next(
(exp for exp in expected if isinstance(exp, list)), None
)
expected_dict = next(
(exp for exp in expected if isinstance(exp, dict)), None
)
if (expected_list, expected_dict) != (None, None):
self.assertParseResultsEquals(
result,
expected_list=expected_list,
expected_dict=expected_dict,
msg=fail_msg or msg,
)
else:
# warning here maybe?
print("no validation for {!r}".format(test_string))
# do this last, in case some specific test results can be reported instead
self.assertTrue(
run_test_success, msg=msg if msg is not None else "failed runTests"
)
@contextmanager
def assertRaisesParseException(self, exc_type=ParseException, msg=None):
with self.assertRaises(exc_type, msg=msg):
yield
if __name__ == "__main__":
selectToken = CaselessLiteral("select")
fromToken = CaselessLiteral("from")
ident = Word(alphas, alphanums + "_$")
columnName = delimitedList(ident, ".", combine=True).setParseAction(upcaseTokens)
columnNameList = Group(delimitedList(columnName)).setName("columns")
columnSpec = ('*' | columnNameList)
tableName = delimitedList(ident, ".", combine=True).setParseAction(upcaseTokens)
tableNameList = Group(delimitedList(tableName)).setName("tables")
simpleSQL = selectToken("command") + columnSpec("columns") + fromToken + tableNameList("tables")
# demo runTests method, including embedded comments in test string
simpleSQL.runTests("""
# '*' as column list and dotted table name
select * from SYS.XYZZY
# caseless match on "SELECT", and casts back to "select"
SELECT * from XYZZY, ABC
# list of column names, and mixed case SELECT keyword
Select AA,BB,CC from Sys.dual
# multiple tables
Select A, B, C from Sys.dual, Table2
# invalid SELECT keyword - should fail
Xelect A, B, C from Sys.dual
# incomplete command - should fail
Select
# invalid column name - should fail
Select ^^^ frox Sys.dual
""")
pyparsing_common.number.runTests("""
100
-100
+100
3.14159
6.02e23
1e-12
""")
# any int or real number, returned as float
pyparsing_common.fnumber.runTests("""
100
-100
+100
3.14159
6.02e23
1e-12
""")
pyparsing_common.hex_integer.runTests("""
100
FF
""")
import uuid
pyparsing_common.uuid.setParseAction(tokenMap(uuid.UUID))
pyparsing_common.uuid.runTests("""
12345678-1234-5678-1234-567812345678
""")
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