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| author | Paul McGuire <ptmcg@users.noreply.github.com> | 2019-11-18 22:41:40 -0600 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2019-11-18 22:41:40 -0600 |
| commit | 0b398062710dc00b952636bcf7b7933f74f125da (patch) | |
| tree | b3f8a2300d1a1669a94afbf90b7915915df8e406 /pyparsing/core.py | |
| parent | bea48a41d40f1c37bea7a718cc06e9b858c8ccbf (diff) | |
| download | pyparsing-git-0b398062710dc00b952636bcf7b7933f74f125da.tar.gz | |
Break up pyparsing.py monolith into sub-modules in a pyparsing package (#162)
* Break up pyparsing.py monolith into sub-modules in a pyparsing package
* Convert relative imports to absolutes
* Reference submodule pyparsing in setup.py modules
* Remove recursive import of pyparsing from setup.py
* Black updates
* setup.py updates - packages vs. modules. use .dev1 for the version
Diffstat (limited to 'pyparsing/core.py')
| -rw-r--r-- | pyparsing/core.py | 4699 |
1 files changed, 4699 insertions, 0 deletions
diff --git a/pyparsing/core.py b/pyparsing/core.py new file mode 100644 index 0000000..15dd95b --- /dev/null +++ b/pyparsing/core.py @@ -0,0 +1,4699 @@ +# +# core.py +# +import string +import copy +import sys +import warnings +import re +import sre_constants +from collections.abc import Iterable +import traceback +import types +from operator import itemgetter +from functools import wraps +from threading import RLock + +from .util import ( + _FifoCache, + _UnboundedCache, + __config_flags, + _collapseAndEscapeRegexRangeChars, + _escapeRegexRangeChars, + _bslash, + _flatten, +) +from pyparsing.exceptions import * +from pyparsing.actions import * +from pyparsing.results import ParseResults, _ParseResultsWithOffset + +system_version = tuple(sys.version_info)[:3] +_MAX_INT = sys.maxsize +str_type = (str, bytes) + +# -*- 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. +# + +__version__ = "3.0.0a1" +__versionTime__ = "13 Oct 2019 05:49 UTC" +__author__ = "Paul McGuire <ptmcg@users.sourceforge.net>" + + +class __compat__(__config_flags): + """ + 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; + maintained for compatibility, but setting to False no longer restores pre-2.3.1 + behavior + """ + + _type_desc = "compatibility" + + collect_all_And_tokens = True + + _all_names = [__ for __ in locals() if not __.startswith("_")] + _fixed_names = """ + collect_all_And_tokens + """.split() + + +class __diag__(__config_flags): + """ + 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 + - 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() + """ + + _type_desc = "diagnostic" + + warn_multiple_tokens_in_named_alternation = False + warn_ungrouped_named_tokens_in_collection = False + warn_name_set_on_empty_Forward = False + warn_on_multiple_string_args_to_oneof = False + enable_debug_on_named_expressions = False + + _all_names = [__ for __ in locals() if not __.startswith("_")] + _warning_names = [name for name in _all_names if name.startswith("warn")] + _debug_names = [name for name in _all_names if name.startswith("enable_debug")] + + @classmethod + def enable_all_warnings(cls): + for name in cls._warning_names: + cls.enable(name) + + +# hide abstract class +del __config_flags + +# 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] + +_generatorType = types.GeneratorType + +alphas = string.ascii_uppercase + string.ascii_lowercase +nums = "0123456789" +hexnums = nums + "ABCDEFabcdef" +alphanums = alphas + nums +printables = "".join(c for c in string.printable if c not in string.whitespace) + + +def _trim_arity(func, maxargs=2): + "decorator to trim function calls to match the arity of the target" + + if func in singleArgBuiltins: + return lambda s, l, t: func(t) + + limit = 0 + found_arity = False + + # traceback return data structure changed in Py3.5 - normalize back to plain tuples + 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]] + + # 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 = 7 + # 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): + nonlocal found_arity, limit + while 1: + try: + ret = func(*args[limit:]) + found_arity = True + return ret + except TypeError: + # re-raise TypeErrors if they did not come from our arity testing + if found_arity: + 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 <= maxargs: + limit += 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 + + +def conditionAsParseAction(fn, message=None, fatal=False): + """ + Function to convert a simple predicate function that returns True or False + into a parse action. Can be used in places when a parse action is required + and ParserElement.addCondition cannot be used (such as when adding a condition + to an operator level in infixNotation). + + 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 + """ + 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 + + +def _defaultStartDebugAction(instring, loc, expr): + print( + ( + "Match " + + str(expr) + + " at loc " + + str(loc) + + "(%d,%d)" % (lineno(loc, instring), col(loc, instring)) + ) + ) + + +def _defaultSuccessDebugAction(instring, startloc, endloc, expr, toks): + print("Matched " + str(expr) + " -> " + str(toks.asList())) + + +def _defaultExceptionDebugAction(instring, loc, expr, exc): + print("Exception raised:" + str(exc)) + + +def nullDebugAction(*args): + """'Do-nothing' debug action, to suppress debugging output during parsing.""" + pass + + +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 + + # update whitespace all parse expressions defined in this module + for expr in _builtin_exprs: + if expr.copyDefaultWhiteChars: + expr.whiteChars = 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 + + 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 + - callDuringTry = boolean to indicate if this method should be called during internal tryParse calls, + default=False + + 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, raise_fatal=False): + try: + return self._parse(instring, loc, doActions=False)[0] + except ParseFatalException: + if raise_fatal: + raise + 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 + + # 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 = _UnboundedCache() + else: + ParserElement.packrat_cache = _FifoCache(cache_size_limit) + ParserElement._parse = ParserElement._parseCache + + def parseString(self, instring, parseAll=False): + """ + Parse a string with respect to the parser definition. This function is intended as the primary interface to the + client code. + + :param instring: The input string to be parsed. + :param parseAll: If set, the entire input string must match the grammar. + :raises ParseException: Raised if ``parseAll`` is set and the input string does not match the whole grammar. + :returns: the parsed data as a :class:`ParseResults` object, which may be accessed as a `list`, a `dict`, or + an object with attributes if the given parser includes results names. + + If the input string is required to match the entire grammar, ``parseAll`` flag must be set to True. This + is also equivalent to ending the grammar with ``StringEnd()``. + + To report proper column numbers, ``parseString`` operates on a copy of the input string where all tabs are + converted to spaces (8 spaces per tab, as per the default in ``string.expandtabs``). If the input string + contains tabs and the grammar uses parse actions that use the ``loc`` argument to index into the string + being parsed, one can ensure a consistent view of the input string by doing one of the following: + + - 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, or + - explicitly expand the tabs in your input string before calling ``parseString``. + + Examples: + + By default, partial matches are OK. + + >>> res = Word('a').parseString('aaaaabaaa') + >>> print(res) + ['aaaaa'] + + The parsing behavior varies by the inheriting class of this abstract class. Please refer to the children + directly to see more examples. + + It raises an exception if parseAll flag is set and instring does not match the whole grammar. + + >>> res = Word('a').parseString('aaaaabaaa', parseAll=True) + Traceback (most recent call last): + ... + pyparsing.ParseException: Expected end of text, found 'b' (at char 5), (line:1, col:6) + """ + + 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, clears out pyparsing internal stack trace + 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 = str(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, clears out pyparsing internal stack trace + 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(str, _flatten(out))) + except ParseBaseException as exc: + if ParserElement.verbose_stacktrace: + raise + else: + # catch and re-raise exception from here, clears out pyparsing internal stack trace + 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, clears out pyparsing internal stack trace + 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, str_type): + other = self._literalStringClass(other) + if not isinstance(other, ParserElement): + warnings.warn( + "Cannot combine element of type {} with ParserElement".format( + type(other).__name__ + ), + 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, str_type): + 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, str_type): + 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, str_type): + 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, str_type): + 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, str_type): + 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, str_type): + 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, str_type): + 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, str_type): + 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, str_type): + 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_type): + key = (key,) + iter(key) + except TypeError: + key = (key, key) + + if len(key) > 2: + warnings.warn( + "only 1 or 2 index arguments supported ({}{})".format( + key[:5], "... [{}]".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, copy_defaults=False): + """ + Overrides the default whitespace chars + """ + self.skipWhitespace = True + self.whiteChars = chars + self.copyDefaultWhiteChars = copy_defaults + 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, str_type): + 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 str(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, clears out pyparsing internal stack trace + raise exc + + def __eq__(self, other): + if self is other: + return True + elif isinstance(other, str_type): + return self.matches(other) + elif isinstance(other, ParserElement): + return vars(self) == vars(other) + return False + + 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(str(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, str_type): + tests = list(map(type(tests).strip, tests.rstrip().splitlines())) + if isinstance(comment, str_type): + 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 = "\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".join(comments), 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( + "{} failed: {}: {}".format( + postParse.__name__, type(e).__name__, e + ) + ) + else: + out.append(result.dump(full=fullDump)) + out.append("") + + if printResults: + 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().__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().__init__(savelist=False) + + +class Empty(Token): + """An empty token, will always match. + """ + + def __init__(self): + super().__init__() + self.name = "Empty" + self.mayReturnEmpty = True + self.mayIndexError = False + + +class NoMatch(Token): + """A token that will never match. + """ + + def __init__(self): + super().__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().__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"' % str(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) + + +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().__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().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().__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().__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().__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 = start + 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().__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 = str(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]+" % _collapseAndEscapeRegexRangeChars( + self.initCharsOrig + ) + elif len(self.initCharsOrig) == 1: + self.reString = "%s[%s]*" % ( + re.escape(self.initCharsOrig), + _collapseAndEscapeRegexRangeChars(self.bodyCharsOrig), + ) + else: + self.reString = "[%s][%s]*" % ( + _collapseAndEscapeRegexRangeChars(self.initCharsOrig), + _collapseAndEscapeRegexRangeChars(self.bodyCharsOrig), + ) + if self.asKeyword: + self.reString = r"\b" + self.reString + r"\b" + + try: + self.re = re.compile(self.reString) + except sre_constants.error: + 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().__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().__init__( + charset, exact=1, asKeyword=asKeyword, excludeChars=excludeChars + ) + self.reString = "[{}]".format(_collapseAndEscapeRegexRangeChars(self.initChars)) + if asKeyword: + self.reString = r"\b{}\b".format(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, or by replacing + the imported `re` module in pyparsing with the `regex` module: + + + 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})") + + import regex + parser = pp.Regex(regex.compile(r'[0-9]')) + + # or + + import pyparsing + pyparsing.re = regex + + # both of these will use the regex module to compile their internal re's + parser = pp.Regex(r'[0-9]') + parser = pp.Word(pp.nums) + + """ + + 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().__init__() + + if isinstance(pattern, str_type): + 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 = str(self) + self.errmsg = "Expected " + self.name + self.mayIndexError = False + self.mayReturnEmpty = True + 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().__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().__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 = str(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, str_type): + # 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().__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().__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 = str(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().__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\00A0": "<NBSP>", + "u\1680": "<OGHAM_SPACE_MARK>", + "u\180E": "<MONGOLIAN_VOWEL_SEPARATOR>", + "u\2000": "<EN_QUAD>", + "u\2001": "<EM_QUAD>", + "u\2002": "<EN_SPACE>", + "u\2003": "<EM_SPACE>", + "u\2004": "<THREE-PER-EM_SPACE>", + "u\2005": "<FOUR-PER-EM_SPACE>", + "u\2006": "<SIX-PER-EM_SPACE>", + "u\2007": "<FIGURE_SPACE>", + "u\2008": "<PUNCTUATION_SPACE>", + "u\2009": "<THIN_SPACE>", + "u\200A": "<HAIR_SPACE>", + "u\200B": "<ZERO_WIDTH_SPACE>", + "u\202F": "<NNBSP>", + "u\205F": "<MMSP>", + "u\3000": "<IDEOGRAPHIC_SPACE>", + } + + def __init__(self, ws=" \t\r\n", min=1, max=0, exact=0): + super().__init__() + self.matchWhite = ws + self.setWhitespaceChars( + "".join(c for c in self.whiteChars if c not in self.matchWhite), + copy_defaults=True, + ) + # ~ 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().__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().__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().__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().__init__() + self.setWhitespaceChars( + ParserElement.DEFAULT_WHITE_CHARS.replace("\n", ""), copy_defaults=False + ) + 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().__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().__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().__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().__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().__init__(savelist) + if isinstance(exprs, _generatorType): + exprs = list(exprs) + + if isinstance(exprs, str_type): + 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, str_type) for expr in exprs): + exprs = ( + self._literalStringClass(e) if isinstance(e, str_type) 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().ignore(other) + for e in self.exprs: + e.ignore(self.ignoreExprs[-1]) + else: + super().ignore(other) + for e in self.exprs: + e.ignore(self.ignoreExprs[-1]) + return self + + def __str__(self): + try: + return super().__str__() + except Exception: + pass + + if self.strRepr is None: + self.strRepr = "%s:(%s)" % (self.__class__.__name__, str(self.exprs)) + return self.strRepr + + def streamline(self): + super().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 " + str(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().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( + "{}: setting results name {!r} on {} expression " + "collides with {!r} on contained expression".format( + "warn_ungrouped_named_tokens_in_collection", + name, + type(self).__name__, + e.resultsName, + ), + stacklevel=3, + ) + + return super()._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().__init__(*args, **kwargs) + self.name = "-" + self.leaveWhitespace() + + def __init__(self, exprs, savelist=True): + 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().__init__(exprs, savelist) + self.mayReturnEmpty = all(e.mayReturnEmpty for e in self.exprs) + self.setWhitespaceChars( + self.exprs[0].whiteChars, copy_defaults=self.exprs[0].copyDefaultWhiteChars + ) + 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().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, str_type): + 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(str(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().__init__(exprs, savelist) + if self.exprs: + self.mayReturnEmpty = any(e.mayReturnEmpty for e in self.exprs) + else: + self.mayReturnEmpty = True + + def streamline(self): + super().streamline() + self.saveAsList = any(e.saveAsList for e in self.exprs) + return self + + def parseImpl(self, instring, loc, doActions=True): + maxExcLoc = -1 + maxException = None + matches = [] + fatals = [] + for e in self.exprs: + try: + loc2 = e.tryParse(instring, loc, raise_fatal=True) + except ParseFatalException as pfe: + pfe.__traceback__ = None + pfe.parserElement = e + fatals.append(pfe) + maxException = None + maxExcLoc = -1 + except ParseException as err: + if not fatals: + 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 fatals: + if len(fatals) > 1: + fatals.sort(key=lambda e: -e.loc) + if fatals[0].loc == fatals[1].loc: + fatals.sort(key=lambda e: (-e.loc, -len(str(e.parserElement)))) + max_fatal = fatals[0] + raise max_fatal + + 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, str_type): + 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(str(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 __diag__.warn_multiple_tokens_in_named_alternation: + if any(isinstance(e, And) for e in self.exprs): + warnings.warn( + "{}: setting results name {!r} on {} expression " + "will return a list of all parsed tokens in an And alternative, " + "in prior versions only the first token was returned".format( + "warn_multiple_tokens_in_named_alternation", + name, + type(self).__name__, + ), + stacklevel=3, + ) + + return super()._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().__init__(exprs, savelist) + if self.exprs: + self.mayReturnEmpty = any(e.mayReturnEmpty for e in self.exprs) + else: + self.mayReturnEmpty = True + + def streamline(self): + super().streamline() + self.saveAsList = any(e.saveAsList for e in self.exprs) + return self + + def parseImpl(self, instring, loc, doActions=True): + maxExcLoc = -1 + maxException = None + fatals = [] + for e in self.exprs: + try: + ret = e._parse(instring, loc, doActions) + return ret + except ParseFatalException as pfe: + pfe.__traceback__ = None + pfe.parserElement = e + fatals.append(pfe) + maxException = None + except ParseException as err: + if not fatals and 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 + if fatals: + if len(fatals) > 1: + fatals.sort(key=lambda e: -e.loc) + if fatals[0].loc == fatals[1].loc: + fatals.sort(key=lambda e: (-e.loc, -len(str(e.parserElement)))) + max_fatal = fatals[0] + raise max_fatal + + 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, str_type): + 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(str(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 __diag__.warn_multiple_tokens_in_named_alternation: + if any(isinstance(e, And) for e in self.exprs): + warnings.warn( + "{}: setting results name {!r} on {} 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()._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().__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().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) + ] + 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 + failed = [] + fatals = [] + while keepMatching: + tmpExprs = tmpReqd + tmpOpt + self.multioptionals + self.multirequired + failed.clear() + fatals.clear() + for e in tmpExprs: + try: + tmpLoc = e.tryParse(instring, tmpLoc, raise_fatal=True) + except ParseFatalException as pfe: + pfe.__traceback__ = None + pfe.parserElement = e + fatals.append(pfe) + failed.append(e) + 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 + + # look for any ParseFatalExceptions + if fatals: + if len(fatals) > 1: + fatals.sort(key=lambda e: -e.loc) + if fatals[0].loc == fatals[1].loc: + fatals.sort(key=lambda e: (-e.loc, -len(str(e.parserElement)))) + max_fatal = fatals[0] + raise max_fatal + + if tmpReqd: + missing = ", ".join(str(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(str(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().__init__(savelist) + if isinstance(expr, str_type): + if issubclass(self._literalStringClass, Token): + expr = self._literalStringClass(expr) + elif issubclass(type(self), self._literalStringClass): + expr = Literal(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, copy_defaults=expr.copyDefaultWhiteChars + ) + 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().ignore(other) + if self.expr is not None: + self.expr.ignore(self.ignoreExprs[-1]) + else: + super().ignore(other) + if self.expr is not None: + self.expr.ignore(self.ignoreExprs[-1]) + return self + + def streamline(self): + super().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().__str__() + except Exception: + pass + + if self.strRepr is None and self.expr is not None: + self.strRepr = "%s:(%s)" % (self.__class__.__name__, str(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().__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().__init__(expr) + self.expr = self.expr().leaveWhitespace() + self.mayReturnEmpty = True + self.mayIndexError = False + self.exact = False + if isinstance(expr, str_type): + 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().__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, " + str(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 = "~{" + str(self.expr) + "}" + + return self.strRepr + + +class _MultipleMatch(ParseElementEnhance): + def __init__(self, expr, stopOn=None): + super().__init__(expr) + self.saveAsList = True + ender = stopOn + if isinstance(ender, str_type): + ender = self._literalStringClass(ender) + self.stopOn(ender) + + def stopOn(self, ender): + if isinstance(ender, str_type): + 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( + "{}: setting results name {!r} on {} expression " + "collides with {!r} on contained expression".format( + "warn_ungrouped_named_tokens_in_collection", + name, + type(self).__name__, + e.resultsName, + ), + stacklevel=3, + ) + + return super()._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 = "{" + str(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().__init__(expr, stopOn=stopOn) + self.mayReturnEmpty = True + + def parseImpl(self, instring, loc, doActions=True): + try: + return super().parseImpl(instring, loc, doActions) + except (ParseException, IndexError): + return loc, ParseResults([], name=self.resultsName) + + def __str__(self): + if hasattr(self, "name"): + return self.name + + if self.strRepr is None: + self.strRepr = "[" + str(self.expr) + "]..." + + return self.strRepr + + +class _NullToken(object): + def __bool__(self): + return False + + 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().__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 = "[" + str(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().__init__(other) + self.ignoreExpr = ignore + self.mayReturnEmpty = True + self.mayIndexError = False + self.includeMatch = include + self.saveAsList = False + if isinstance(failOn, str_type): + self.failOn = self._literalStringClass(failOn) + else: + self.failOn = failOn + self.errmsg = "No match found for " + str(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().__init__(other, savelist=False) + + def __lshift__(self, other): + if isinstance(other, str_type): + 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, copy_defaults=self.expr.copyDefaultWhiteChars + ) + 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 = str(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().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( + "{}: setting results name {!r} on {} expression " + "that has no contained expression".format( + "warn_name_set_on_empty_Forward", name, type(self).__name__ + ), + stacklevel=3, + ) + + return super()._setResultsName(name, listAllMatches) + + +class TokenConverter(ParseElementEnhance): + """ + Abstract subclass of :class:`ParseExpression`, for converting parsed results. + """ + + def __init__(self, expr, savelist=False): + super().__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().__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().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().__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().__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 = str(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 + + +# 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"\[]-*.$+^?()~ ", exact=2).setParseAction( + lambda s, l, t: t[0][1] +) +_escapedHexChar = Regex(r"\\0?[xX][0-9a-fA-F]+").setParseAction( + lambda s, l, t: chr(int(t[0].lstrip(r"\0x"), 16)) +) +_escapedOctChar = Regex(r"\\0[0-7]+").setParseAction( + lambda s, l, t: chr(int(t[0][1:], 8)) +) +_singleChar = ( + _escapedPunc | _escapedHexChar | _escapedOctChar | CharsNotIn(r"\]", 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(chr(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 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 + + +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("u" + quotedString.copy()).setName("unicode string literal") + + +alphas8bit = srange(r"[\0xc0-\0xd6\0xd8-\0xf6\0xf8-\0xff]") +punc8bit = srange(r"[\0xa1-\0xbf\0xd7\0xf7]") + +# build list of built-in expressions, for future reference if a global default value +# gets updated +_builtin_exprs = [v for v in vars().values() if isinstance(v, ParserElement)] |