Module pyparsing :: Class PrecededBy
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Class PrecededBy

source code

     object --+        
  ParserElement --+    
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.


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.


   # VB-style variable names with type prefixes
   int_var = PrecededBy("#") + pyparsing_common.identifier
   str_var = PrecededBy("$") + pyparsing_common.identifier
Nested Classes [hide private]
Instance Methods [hide private]
__init__(self, expr, retreat=None)
x.__init__(...) initializes x; see help(type(x)) for signature
source code
parseImpl(self, instring, loc=0, doActions=True) source code

Inherited from ParseElementEnhance: __str__, checkRecursion, ignore, leaveWhitespace, streamline, validate

Inherited from ParserElement: __add__, __and__, __call__, __eq__, __getitem__, __hash__, __invert__, __iter__, __mul__, __ne__, __or__, __radd__, __rand__, __repr__, __req__, __rmul__, __rne__, __ror__, __rsub__, __rxor__, __sub__, __xor__, addCondition, addParseAction, canParseNext, copy, matches, parseFile, parseString, parseWithTabs, postParse, preParse, runTests, scanString, searchString, setBreak, setDebug, setDebugActions, setFailAction, setName, setParseAction, setResultsName, setWhitespaceChars, split, suppress, transformString, tryParse

Inherited from object: __delattr__, __format__, __getattribute__, __new__, __reduce__, __reduce_ex__, __setattr__, __sizeof__, __subclasshook__

Static Methods [hide private]

Inherited from ParserElement: enablePackrat, inlineLiteralsUsing, resetCache, setDefaultWhitespaceChars

Class Variables [hide private]

Inherited from ParserElement: DEFAULT_WHITE_CHARS, packrat_cache, packrat_cache_lock, packrat_cache_stats, verbose_stacktrace

Inherited from ParserElement (private): _packratEnabled

Properties [hide private]

Inherited from object: __class__

Method Details [hide private]

__init__(self, expr, retreat=None)

source code 

x.__init__(...) initializes x; see help(type(x)) for signature

Overrides: object.__init__
(inherited documentation)

parseImpl(self, instring, loc=0, doActions=True)

source code 
Overrides: ParserElement.parseImpl