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pyparsing.py
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# module pyparsing.py
#
# Copyright (c) 2003-2009 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.
#
#from __future__ import generators
__doc__ = \
"""
pyparsing module - Classes and methods to define and execute parsing grammars
The pyparsing module is an alternative approach to creating and executing simple grammars,
vs. the traditional lex/yacc approach, or the use of regular expressions. With pyparsing, you
don't need to learn a new syntax for defining grammars or matching expressions - the parsing module
provides a library of classes that you use to construct the grammar directly in Python.
Here is a program to parse "Hello, World!" (or any greeting of the form "<salutation>, <addressee>!")::
from pyparsing import Word, alphas
# define grammar of a greeting
greet = Word( alphas ) + "," + Word( alphas ) + "!"
hello = "Hello, World!"
print hello, "->", greet.parseString( hello )
The program outputs the following::
Hello, World! -> ['Hello', ',', 'World', '!']
The Python representation of the grammar is quite readable, owing to the self-explanatory
class names, and the use of '+', '|' and '^' operators.
The parsed results returned from parseString() can be accessed as a nested list, a dictionary, or an
object with named attributes.
The pyparsing module handles some of the problems that are typically vexing when writing text parsers:
- extra or missing whitespace (the above program will also handle "Hello,World!", "Hello , World !", etc.)
- quoted strings
- embedded comments
"""
__version__ = "1.5.2"
__versionTime__ = "17 February 2009 19:45"
__author__ = "Paul McGuire <ptmcg@users.sourceforge.net>"
import string
from weakref import ref as wkref
import copy
import sys
import warnings
import re
import sre_constants
#~ sys.stderr.write( "testing pyparsing module, version %s, %s\n" % (__version__,__versionTime__ ) )
__all__ = [
'And', 'CaselessKeyword', 'CaselessLiteral', 'CharsNotIn', 'Combine', 'Dict', 'Each', 'Empty',
'FollowedBy', 'Forward', 'GoToColumn', 'Group', 'Keyword', 'LineEnd', 'LineStart', 'Literal',
'MatchFirst', 'NoMatch', 'NotAny', 'OneOrMore', 'OnlyOnce', 'Optional', 'Or',
'ParseBaseException', 'ParseElementEnhance', 'ParseException', 'ParseExpression', 'ParseFatalException',
'ParseResults', 'ParseSyntaxException', 'ParserElement', 'QuotedString', 'RecursiveGrammarException',
'Regex', 'SkipTo', 'StringEnd', 'StringStart', 'Suppress', 'Token', 'TokenConverter', 'Upcase',
'White', 'Word', 'WordEnd', 'WordStart', 'ZeroOrMore',
'alphanums', 'alphas', 'alphas8bit', 'anyCloseTag', 'anyOpenTag', 'cStyleComment', 'col',
'commaSeparatedList', 'commonHTMLEntity', 'countedArray', 'cppStyleComment', 'dblQuotedString',
'dblSlashComment', 'delimitedList', 'dictOf', 'downcaseTokens', 'empty', 'getTokensEndLoc', 'hexnums',
'htmlComment', 'javaStyleComment', 'keepOriginalText', 'line', 'lineEnd', 'lineStart', 'lineno',
'makeHTMLTags', 'makeXMLTags', 'matchOnlyAtCol', 'matchPreviousExpr', 'matchPreviousLiteral',
'nestedExpr', 'nullDebugAction', 'nums', 'oneOf', 'opAssoc', 'operatorPrecedence', 'printables',
'punc8bit', 'pythonStyleComment', 'quotedString', 'removeQuotes', 'replaceHTMLEntity',
'replaceWith', 'restOfLine', 'sglQuotedString', 'srange', 'stringEnd',
'stringStart', 'traceParseAction', 'unicodeString', 'upcaseTokens', 'withAttribute',
'indentedBlock', 'originalTextFor',
]
"""
Detect if we are running version 3.X and make appropriate changes
Robert A. Clark
"""
if sys.version_info[0] > 2:
_PY3K = True
_MAX_INT = sys.maxsize
basestring = str
else:
_PY3K = False
_MAX_INT = sys.maxint
if not _PY3K:
def _ustr(obj):
"""Drop-in replacement for str(obj) that tries to be Unicode friendly. It first tries
str(obj). If that fails with a UnicodeEncodeError, then it tries unicode(obj). It
then < returns the unicode object | encodes it with the default encoding | ... >.
"""
if isinstance(obj,unicode):
return obj
try:
# If this works, then _ustr(obj) has the same behaviour as str(obj), so
# it won't break any existing code.
return str(obj)
except UnicodeEncodeError:
# The Python docs (http://docs.python.org/ref/customization.html#l2h-182)
# state that "The return value must be a string object". However, does a
# unicode object (being a subclass of basestring) count as a "string
# object"?
# If so, then return a unicode object:
return unicode(obj)
# Else encode it... but how? There are many choices... :)
# Replace unprintables with escape codes?
#return unicode(obj).encode(sys.getdefaultencoding(), 'backslashreplace_errors')
# Replace unprintables with question marks?
#return unicode(obj).encode(sys.getdefaultencoding(), 'replace')
# ...
else:
_ustr = str
unichr = chr
if not _PY3K:
def _str2dict(strg):
return dict( [(c,0) for c in strg] )
else:
_str2dict = set
def _xml_escape(data):
"""Escape &, <, >, ", ', etc. in a string of data."""
# ampersand must be replaced first
from_symbols = '&><"\''
to_symbols = ['&'+s+';' for s in "amp gt lt quot apos".split()]
for from_,to_ in zip(from_symbols, to_symbols):
data = data.replace(from_, to_)
return data
class _Constants(object):
pass
if not _PY3K:
alphas = string.lowercase + string.uppercase
else:
alphas = string.ascii_lowercase + string.ascii_uppercase
nums = string.digits
hexnums = nums + "ABCDEFabcdef"
alphanums = alphas + nums
_bslash = chr(92)
printables = "".join( [ c for c in string.printable if c not in string.whitespace ] )
class ParseBaseException(Exception):
"""base exception class for all parsing runtime exceptions"""
# Performance tuning: we construct a *lot* of these, so keep this
# constructor as small and fast as possible
def __init__( self, pstr, loc=0, msg=None, elem=None ):
self.loc = loc
if msg is None:
self.msg = pstr
self.pstr = ""
else:
self.msg = msg
self.pstr = pstr
self.parserElement = elem
def __getattr__( self, aname ):
"""supported attributes by name are:
- lineno - returns the line number of the exception text
- col - returns the column number of the exception text
- line - returns the line containing the exception text
"""
if( aname == "lineno" ):
return lineno( self.loc, self.pstr )
elif( aname in ("col", "column") ):
return col( self.loc, self.pstr )
elif( aname == "line" ):
return line( self.loc, self.pstr )
else:
raise AttributeError(aname)
def __str__( self ):
return "%s (at char %d), (line:%d, col:%d)" % \
( self.msg, self.loc, self.lineno, self.column )
def __repr__( self ):
return _ustr(self)
def markInputline( self, markerString = ">!<" ):
"""Extracts the exception line from the input string, and marks
the location of the exception with a special symbol.
"""
line_str = self.line
line_column = self.column - 1
if markerString:
line_str = "".join( [line_str[:line_column],
markerString, line_str[line_column:]])
return line_str.strip()
def __dir__(self):
return "loc msg pstr parserElement lineno col line " \
"markInputLine __str__ __repr__".split()
class ParseException(ParseBaseException):
"""exception thrown when parse expressions don't match class;
supported attributes by name are:
- lineno - returns the line number of the exception text
- col - returns the column number of the exception text
- line - returns the line containing the exception text
"""
pass
class ParseFatalException(ParseBaseException):
"""user-throwable exception thrown when inconsistent parse content
is found; stops all parsing immediately"""
pass
class ParseSyntaxException(ParseFatalException):
"""just like ParseFatalException, but thrown internally when an
ErrorStop indicates that parsing is to stop immediately because
an unbacktrackable syntax error has been found"""
def __init__(self, pe):
super(ParseSyntaxException, self).__init__(
pe.pstr, pe.loc, pe.msg, pe.parserElement)
#~ class ReparseException(ParseBaseException):
#~ """Experimental class - parse actions can raise this exception to cause
#~ pyparsing to reparse the input string:
#~ - with a modified input string, and/or
#~ - with a modified start location
#~ Set the values of the ReparseException in the constructor, and raise the
#~ exception in a parse action to cause pyparsing to use the new string/location.
#~ Setting the values as None causes no change to be made.
#~ """
#~ def __init_( self, newstring, restartLoc ):
#~ self.newParseText = newstring
#~ self.reparseLoc = restartLoc
class RecursiveGrammarException(Exception):
"""exception thrown by validate() if the grammar could be improperly recursive"""
def __init__( self, parseElementList ):
self.parseElementTrace = parseElementList
def __str__( self ):
return "RecursiveGrammarException: %s" % self.parseElementTrace
class _ParseResultsWithOffset(object):
def __init__(self,p1,p2):
self.tup = (p1,p2)
def __getitem__(self,i):
return self.tup[i]
def __repr__(self):
return repr(self.tup)
def setOffset(self,i):
self.tup = (self.tup[0],i)
class ParseResults(object):
"""Structured parse results, to provide multiple means of access to the parsed data:
- as a list (len(results))
- by list index (results[0], results[1], etc.)
- by attribute (results.<resultsName>)
"""
__slots__ = ( "__toklist", "__tokdict", "__doinit", "__name", "__parent", "__accumNames", "__weakref__" )
def __new__(cls, toklist, name=None, asList=True, modal=True ):
if isinstance(toklist, cls):
return toklist
retobj = object.__new__(cls)
retobj.__doinit = True
return retobj
# Performance tuning: we construct a *lot* of these, so keep this
# constructor as small and fast as possible
def __init__( self, toklist, name=None, asList=True, modal=True ):
if self.__doinit:
self.__doinit = False
self.__name = None
self.__parent = None
self.__accumNames = {}
if isinstance(toklist, list):
self.__toklist = toklist[:]
else:
self.__toklist = [toklist]
self.__tokdict = dict()
if name:
if not modal:
self.__accumNames[name] = 0
if isinstance(name,int):
name = _ustr(name) # will always return a str, but use _ustr for consistency
self.__name = name
if not toklist in (None,'',[]):
if isinstance(toklist,basestring):
toklist = [ toklist ]
if asList:
if isinstance(toklist,ParseResults):
self[name] = _ParseResultsWithOffset(toklist.copy(),0)
else:
self[name] = _ParseResultsWithOffset(ParseResults(toklist[0]),0)
self[name].__name = name
else:
try:
self[name] = toklist[0]
except (KeyError,TypeError,IndexError):
self[name] = toklist
def __getitem__( self, i ):
if isinstance( i, (int,slice) ):
return self.__toklist[i]
else:
if i not in self.__accumNames:
return self.__tokdict[i][-1][0]
else:
return ParseResults([ v[0] for v in self.__tokdict[i] ])
def __setitem__( self, k, v ):
if isinstance(v,_ParseResultsWithOffset):
self.__tokdict[k] = self.__tokdict.get(k,list()) + [v]
sub = v[0]
elif isinstance(k,int):
self.__toklist[k] = v
sub = v
else:
self.__tokdict[k] = self.__tokdict.get(k,list()) + [_ParseResultsWithOffset(v,0)]
sub = v
if isinstance(sub,ParseResults):
sub.__parent = wkref(self)
def __delitem__( self, i ):
if isinstance(i,(int,slice)):
mylen = len( self.__toklist )
del self.__toklist[i]
# convert int to slice
if isinstance(i, int):
if i < 0:
i += mylen
i = slice(i, i+1)
# get removed indices
removed = list(range(*i.indices(mylen)))
removed.reverse()
# fixup indices in token dictionary
for name in self.__tokdict:
occurrences = self.__tokdict[name]
for j in removed:
for k, (value, position) in enumerate(occurrences):
occurrences[k] = _ParseResultsWithOffset(value, position - (position > j))
else:
del self.__tokdict[i]
def __contains__( self, k ):
return k in self.__tokdict
def __len__( self ): return len( self.__toklist )
def __bool__(self): return len( self.__toklist ) > 0
__nonzero__ = __bool__
def __iter__( self ): return iter( self.__toklist )
def __reversed__( self ): return iter( reversed(self.__toklist) )
def keys( self ):
"""Returns all named result keys."""
return self.__tokdict.keys()
def pop( self, index=-1 ):
"""Removes and returns item at specified index (default=last).
Will work with either numeric indices or dict-key indicies."""
ret = self[index]
del self[index]
return ret
def get(self, key, defaultValue=None):
"""Returns named result matching the given key, or if there is no
such name, then returns the given defaultValue or None if no
defaultValue is specified."""
if key in self:
return self[key]
else:
return defaultValue
def insert( self, index, insStr ):
self.__toklist.insert(index, insStr)
# fixup indices in token dictionary
for name in self.__tokdict:
occurrences = self.__tokdict[name]
for k, (value, position) in enumerate(occurrences):
occurrences[k] = _ParseResultsWithOffset(value, position + (position > index))
def items( self ):
"""Returns all named result keys and values as a list of tuples."""
return [(k,self[k]) for k in self.__tokdict]
def values( self ):
"""Returns all named result values."""
return [ v[-1][0] for v in self.__tokdict.values() ]
def __getattr__( self, name ):
if name not in self.__slots__:
if name in self.__tokdict:
if name not in self.__accumNames:
return self.__tokdict[name][-1][0]
else:
return ParseResults([ v[0] for v in self.__tokdict[name] ])
else:
return ""
return None
def __add__( self, other ):
ret = self.copy()
ret += other
return ret
def __iadd__( self, other ):
if other.__tokdict:
offset = len(self.__toklist)
addoffset = ( lambda a: (a<0 and offset) or (a+offset) )
otheritems = other.__tokdict.items()
otherdictitems = [(k, _ParseResultsWithOffset(v[0],addoffset(v[1])) )
for (k,vlist) in otheritems for v in vlist]
for k,v in otherdictitems:
self[k] = v
if isinstance(v[0],ParseResults):
v[0].__parent = wkref(self)
self.__toklist += other.__toklist
self.__accumNames.update( other.__accumNames )
del other
return self
def __repr__( self ):
return "(%s, %s)" % ( repr( self.__toklist ), repr( self.__tokdict ) )
def __str__( self ):
out = "["
sep = ""
for i in self.__toklist:
if isinstance(i, ParseResults):
out += sep + _ustr(i)
else:
out += sep + repr(i)
sep = ", "
out += "]"
return out
def _asStringList( self, sep='' ):
out = []
for item in self.__toklist:
if out and sep:
out.append(sep)
if isinstance( item, ParseResults ):
out += item._asStringList()
else:
out.append( _ustr(item) )
return out
def asList( self ):
"""Returns the parse results as a nested list of matching tokens, all converted to strings."""
out = []
for res in self.__toklist:
if isinstance(res,ParseResults):
out.append( res.asList() )
else:
out.append( res )
return out
def asDict( self ):
"""Returns the named parse results as dictionary."""
return dict( self.items() )
def copy( self ):
"""Returns a new copy of a ParseResults object."""
ret = ParseResults( self.__toklist )
ret.__tokdict = self.__tokdict.copy()
ret.__parent = self.__parent
ret.__accumNames.update( self.__accumNames )
ret.__name = self.__name
return ret
def asXML( self, doctag=None, namedItemsOnly=False, indent="", formatted=True ):
"""Returns the parse results as XML. Tags are created for tokens and lists that have defined results names."""
nl = "\n"
out = []
namedItems = dict( [ (v[1],k) for (k,vlist) in self.__tokdict.items()
for v in vlist ] )
nextLevelIndent = indent + " "
# collapse out indents if formatting is not desired
if not formatted:
indent = ""
nextLevelIndent = ""
nl = ""
selfTag = None
if doctag is not None:
selfTag = doctag
else:
if self.__name:
selfTag = self.__name
if not selfTag:
if namedItemsOnly:
return ""
else:
selfTag = "ITEM"
out += [ nl, indent, "<", selfTag, ">" ]
worklist = self.__toklist
for i,res in enumerate(worklist):
if isinstance(res,ParseResults):
if i in namedItems:
out += [ res.asXML(namedItems[i],
namedItemsOnly and doctag is None,
nextLevelIndent,
formatted)]
else:
out += [ res.asXML(None,
namedItemsOnly and doctag is None,
nextLevelIndent,
formatted)]
else:
# individual token, see if there is a name for it
resTag = None
if i in namedItems:
resTag = namedItems[i]
if not resTag:
if namedItemsOnly:
continue
else:
resTag = "ITEM"
xmlBodyText = _xml_escape(_ustr(res))
out += [ nl, nextLevelIndent, "<", resTag, ">",
xmlBodyText,
"</", resTag, ">" ]
out += [ nl, indent, "</", selfTag, ">" ]
return "".join(out)
def __lookup(self,sub):
for k,vlist in self.__tokdict.items():
for v,loc in vlist:
if sub is v:
return k
return None
def getName(self):
"""Returns the results name for this token expression."""
if self.__name:
return self.__name
elif self.__parent:
par = self.__parent()
if par:
return par.__lookup(self)
else:
return None
elif (len(self) == 1 and
len(self.__tokdict) == 1 and
self.__tokdict.values()[0][0][1] in (0,-1)):
return self.__tokdict.keys()[0]
else:
return None
def dump(self,indent='',depth=0):
"""Diagnostic method for listing out the contents of a ParseResults.
Accepts an optional indent argument so that this string can be embedded
in a nested display of other data."""
out = []
out.append( indent+_ustr(self.asList()) )
keys = self.items()
keys.sort()
for k,v in keys:
if out:
out.append('\n')
out.append( "%s%s- %s: " % (indent,(' '*depth), k) )
if isinstance(v,ParseResults):
if v.keys():
#~ out.append('\n')
out.append( v.dump(indent,depth+1) )
#~ out.append('\n')
else:
out.append(_ustr(v))
else:
out.append(_ustr(v))
#~ out.append('\n')
return "".join(out)
# add support for pickle protocol
def __getstate__(self):
return ( self.__toklist,
( self.__tokdict.copy(),
self.__parent is not None and self.__parent() or None,
self.__accumNames,
self.__name ) )
def __setstate__(self,state):
self.__toklist = state[0]
self.__tokdict, \
par, \
inAccumNames, \
self.__name = state[1]
self.__accumNames = {}
self.__accumNames.update(inAccumNames)
if par is not None:
self.__parent = wkref(par)
else:
self.__parent = None
def __dir__(self):
return dir(super(ParseResults,self)) + self.keys()
def col (loc,strg):
"""Returns current column within a string, counting newlines as line separators.
The first column is number 1.
Note: the default parsing behavior is to expand tabs in the input string
before starting the parsing process. See L{I{ParserElement.parseString}<ParserElement.parseString>} for more information
on parsing strings containing <TAB>s, and suggested methods to maintain a
consistent view of the parsed string, the parse location, and line and column
positions within the parsed string.
"""
return (loc<len(strg) and strg[loc] == '\n') and 1 or loc - strg.rfind("\n", 0, loc)
def lineno(loc,strg):
"""Returns current line number within a string, counting newlines as line separators.
The first line is number 1.
Note: the default parsing behavior is to expand tabs in the input string
before starting the parsing process. See L{I{ParserElement.parseString}<ParserElement.parseString>} for more information
on parsing strings containing <TAB>s, and suggested methods to maintain a
consistent view of the parsed string, the parse location, and line and column
positions within the parsed string.
"""
return strg.count("\n",0,loc) + 1
def line( loc, strg ):
"""Returns the line of text containing loc within a string, counting newlines as line separators.
"""
lastCR = strg.rfind("\n", 0, loc)
nextCR = strg.find("\n", loc)
if nextCR > 0:
return strg[lastCR+1:nextCR]
else:
return strg[lastCR+1:]
def _defaultStartDebugAction( instring, loc, expr ):
print ("Match " + _ustr(expr) + " at loc " + _ustr(loc) + "(%d,%d)" % ( lineno(loc,instring), col(loc,instring) ))
def _defaultSuccessDebugAction( instring, startloc, endloc, expr, toks ):
print ("Matched " + _ustr(expr) + " -> " + str(toks.asList()))
def _defaultExceptionDebugAction( instring, loc, expr, exc ):
print ("Exception raised:" + _ustr(exc))
def nullDebugAction(*args):
"""'Do-nothing' debug action, to suppress debugging output during parsing."""
pass
class ParserElement(object):
"""Abstract base level parser element class."""
DEFAULT_WHITE_CHARS = " \n\t\r"
def setDefaultWhitespaceChars( chars ):
"""Overrides the default whitespace chars
"""
ParserElement.DEFAULT_WHITE_CHARS = chars
setDefaultWhitespaceChars = staticmethod(setDefaultWhitespaceChars)
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 = 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 ParserElement. Useful for defining different parse actions
for the same parsing pattern, using copies of the original parse element."""
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, for use in debugging."""
self.name = name
self.errmsg = "Expected " + self.name
if hasattr(self,"exception"):
self.exception.msg = self.errmsg
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 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.
"""
newself = self.copy()
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
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 _normalizeParseActionArgs( f ):
"""Internal method used to decorate parse actions that take fewer than 3 arguments,
so that all parse actions can be called as f(s,l,t)."""
STAR_ARGS = 4
try:
restore = None
if isinstance(f,type):
restore = f
f = f.__init__
if not _PY3K:
codeObj = f.func_code
else:
codeObj = f.code
if codeObj.co_flags & STAR_ARGS:
return f
numargs = codeObj.co_argcount
if not _PY3K:
if hasattr(f,"im_self"):
numargs -= 1
else:
if hasattr(f,"__self__"):
numargs -= 1
if restore:
f = restore
except AttributeError:
try:
if not _PY3K:
call_im_func_code = f.__call__.im_func.func_code
else:
call_im_func_code = f.__code__
# not a function, must be a callable object, get info from the
# im_func binding of its bound __call__ method
if call_im_func_code.co_flags & STAR_ARGS:
return f
numargs = call_im_func_code.co_argcount
if not _PY3K:
if hasattr(f.__call__,"im_self"):
numargs -= 1
else:
if hasattr(f.__call__,"__self__"):
numargs -= 0
except AttributeError:
if not _PY3K:
call_func_code = f.__call__.func_code
else:
call_func_code = f.__call__.__code__
# not a bound method, get info directly from __call__ method
if call_func_code.co_flags & STAR_ARGS:
return f
numargs = call_func_code.co_argcount
if not _PY3K:
if hasattr(f.__call__,"im_self"):
numargs -= 1
else:
if hasattr(f.__call__,"__self__"):
numargs -= 1
#~ print ("adding function %s with %d args" % (f.func_name,numargs))
if numargs == 3:
return f
else:
if numargs > 3:
def tmp(s,l,t):
return f(f.__call__.__self__, s,l,t)
if numargs == 2:
def tmp(s,l,t):
return f(l,t)
elif numargs == 1:
def tmp(s,l,t):
return f(t)
else: #~ numargs == 0:
def tmp(s,l,t):
return f()
try:
tmp.__name__ = f.__name__
except (AttributeError,TypeError):
# no need for special handling if attribute doesnt exist
pass
try:
tmp.__doc__ = f.__doc__
except (AttributeError,TypeError):
# no need for special handling if attribute doesnt exist
pass
try:
tmp.__dict__.update(f.__dict__)
except (AttributeError,TypeError):
# no need for special handling if attribute doesnt exist
pass
return tmp
_normalizeParseActionArgs = staticmethod(_normalizeParseActionArgs)
def setParseAction( self, *fns, **kwargs ):
"""Define action 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 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.
Note: the default parsing behavior is to expand tabs in the input string
before starting the parsing process. See L{I{parseString}<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.
"""
self.parseAction = list(map(self._normalizeParseActionArgs, list(fns)))
self.callDuringTry = ("callDuringTry" in kwargs and kwargs["callDuringTry"])
return self
def addParseAction( self, *fns, **kwargs ):
"""Add parse action to expression's list of parse actions. See L{I{setParseAction}<setParseAction>}."""
self.parseAction += list(map(self._normalizeParseActionArgs, list(fns)))
self.callDuringTry = self.callDuringTry or ("callDuringTry" in kwargs and kwargs["callDuringTry"])
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 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 ):
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[0] ):
self.debugActions[0]( instring, loc, self )
if callPreParse and self.callPreparse:
preloc = self.preParse( instring, loc )
else:
preloc = loc
tokensStart = loc
try:
try:
loc,tokens = self.parseImpl( instring, preloc, doActions )
except IndexError:
raise ParseException( instring, len(instring), self.errmsg, self )
except ParseBaseException, err:
#~ print ("Exception raised:", err)
if self.debugActions[2]:
self.debugActions[2]( 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 = loc
if self.mayIndexError or loc >= 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:
tokens = fn( instring, tokensStart, retTokens )
if tokens is not None:
retTokens = ParseResults( tokens,
self.resultsName,
asList=self.saveAsList and isinstance(tokens,(ParseResults,list)),
modal=self.modalResults )
except ParseBaseException, err:
#~ print "Exception raised in user parse action:", err
if (self.debugActions[2] ):
self.debugActions[2]( instring, tokensStart, self, err )
raise
else:
for fn in self.parseAction:
tokens = fn( instring, tokensStart, retTokens )
if tokens is not None:
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[1] ):
self.debugActions[1]( instring, tokensStart, loc, self, retTokens )
return loc, retTokens
def tryParse( self, instring, loc ):
try:
return self._parse( instring, loc, doActions=False )[0]
except ParseFatalException:
raise ParseException( instring, loc, self.errmsg, self)
# 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 ):
lookup = (self,instring,loc,callPreParse,doActions)
if lookup in ParserElement._exprArgCache:
value = ParserElement._exprArgCache[ lookup ]
if isinstance(value,Exception):
raise value
return value
else:
try:
value = self._parseNoCache( instring, loc, doActions, callPreParse )
ParserElement._exprArgCache[ lookup ] = (value[0],value[1].copy())
return value
except ParseBaseException, pe:
ParserElement._exprArgCache[ lookup ] = pe
raise
_parse = _parseNoCache
# argument cache for optimizing repeated calls when backtracking through recursive expressions
_exprArgCache = {}
def resetCache():
ParserElement._exprArgCache.clear()
resetCache = staticmethod(resetCache)
_packratEnabled = False
def enablePackrat():
"""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.
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 ParserElement.enablePackrat(). If
your program uses psyco to "compile as you go", you must call
enablePackrat before calling psyco.full(). If you do not do this,
Python will crash. For best results, call enablePackrat() immediately
after importing pyparsing.
"""
if not ParserElement._packratEnabled:
ParserElement._packratEnabled = True
ParserElement._parse = ParserElement._parseCache
enablePackrat = staticmethod(enablePackrat)
def parseString( self, instring, parseAll=False ):
"""Execute the parse expression with the given string.
This is the main interface to the client code, once the complete
expression has been built.
If you want the grammar to require that the entire input string be
successfully parsed, then set parseAll to True (equivalent to ending
the grammar with StringEnd()).
Note: parseString implicitly calls expandtabs() on the input string,
in order to report proper column numbers in parse actions.
If the input string contains tabs and
the grammar uses parse actions that use the loc argument to index into the
string being parsed, you can ensure you have a consistent view of the input
string by:
- calling parseWithTabs on your grammar before calling parseString
(see L{I{parseWithTabs}<parseWithTabs>})
- define your parse action using the full (s,loc,toks) signature, and
reference the input string using the parse action's s argument
- explictly expand the tabs in your input string before calling
parseString
"""
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 )
StringEnd()._parse( instring, loc )
except ParseBaseException, exc:
# 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 ):
"""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.
Note that the start and end locations are reported relative to the string
being parsed. See L{I{parseString}<parseString>} for more information on parsing
strings with embedded tabs."""
if not self.streamlined:
self.streamline()
for e in self.ignoreExprs:
e.streamline()
if not self.keepTabs:
instring = _ustr(instring).expandtabs()
instrlen = len(instring)
loc = 0
preparseFn = self.preParse
parseFn = self._parse
ParserElement.resetCache()
matches = 0
try:
while loc <= instrlen and matches < maxMatches:
try:
preloc = preparseFn( instring, loc )
nextLoc,tokens = parseFn( instring, preloc, callPreParse=False )
except ParseException:
loc = preloc+1
else:
matches += 1
yield tokens, preloc, nextLoc
loc = nextLoc
except ParseBaseException, pe:
raise pe
def transformString( self, instring ):
"""Extension to 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."""
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:])
return "".join(map(_ustr,out))
except ParseBaseException, pe:
raise pe
def searchString( self, instring, maxMatches=_MAX_INT ):
"""Another extension to 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.
"""
try:
return ParseResults([ t for t,s,e in self.scanString( instring, maxMatches ) ])
except ParseBaseException, pe:
raise pe
def __add__(self, other ):
"""Implementation of + operator - returns And"""
if isinstance( other, basestring ):
other = Literal( other )
if not isinstance( other, ParserElement ):
warnings.warn("Cannot combine element of type %s with ParserElement" % type(other),
SyntaxWarning, stacklevel=2)
return None
return And( [ self, other ] )
def __radd__(self, other ):
"""Implementation of + operator when left operand is not a ParserElement"""
if isinstance( other, basestring ):
other = Literal( 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 And with error stop"""
if isinstance( other, basestring ):
other = Literal( other )
if not isinstance( other, ParserElement ):
warnings.warn("Cannot combine element of type %s with ParserElement" % type(other),
SyntaxWarning, stacklevel=2)
return None
return And( [ self, And._ErrorStop(), other ] )
def __rsub__(self, other ):
"""Implementation of - operator when left operand is not a ParserElement"""
if isinstance( other, basestring ):
other = Literal( 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):
if isinstance(other,int):
minElements, optElements = other,0
elif isinstance(other,tuple):
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 MatchFirst"""
if isinstance( other, basestring ):
other = Literal( 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 ParserElement"""
if isinstance( other, basestring ):
other = Literal( 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 Or"""
if isinstance( other, basestring ):
other = Literal( 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 ParserElement"""
if isinstance( other, basestring ):
other = Literal( 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 Each"""
if isinstance( other, basestring ):
other = Literal( 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 ParserElement"""
if isinstance( other, basestring ):
other = Literal( 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 NotAny"""
return NotAny( self )
def __call__(self, name):
"""Shortcut for setResultsName, with listAllMatches=default::
userdata = Word(alphas).setResultsName("name") + Word(nums+"-").setResultsName("socsecno")
could be written as::
userdata = Word(alphas)("name") + Word(nums+"-")("socsecno")
"""
return self.setResultsName(name)
def suppress( self ):
"""Suppresses the output of this 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
ParserElement's defined pattern. This is normally only used internally by
the pyparsing module, but may be needed in some whitespace-sensitive grammars.
"""
self.skipWhitespace = False
return self
def setWhitespaceChars( self, chars ):
"""Overrides the default whitespace chars
"""
self.skipWhitespace = True
self.whiteChars = chars
self.copyDefaultWhiteChars = False
return self
def parseWithTabs( self ):
"""Overrides default behavior to expand <TAB>s to spaces before parsing the input string.
Must be called before parseString when the input grammar contains elements that
match <TAB> characters."""
self.keepTabs = True
return self
def ignore( self, other ):
"""Define expression to be ignored (e.g., comments) while doing pattern
matching; may be called repeatedly, to define multiple comment or other
ignorable patterns.
"""
if isinstance( other, Suppress ):
if other not in self.ignoreExprs:
self.ignoreExprs.append( other )
else:
self.ignoreExprs.append( Suppress( other ) )
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."""
if flag:
self.setDebugActions( _defaultStartDebugAction, _defaultSuccessDebugAction, _defaultExceptionDebugAction )
else:
self.debug = False
return self
def __str__( self ):
return self.name
def __repr__( self ):
return _ustr(self)
def streamline( self ):
self.streamlined = True
self.strRepr = None
return self
def checkRecursion( self, parseElementList ):
pass
def validate( self, validateTrace=[] ):
"""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:
f = open(file_or_filename, "rb")
file_contents = f.read()
f.close()
try:
return self.parseString(file_contents, parseAll)
except ParseBaseException, exc:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc
def getException(self):
return ParseException("",0,self.errmsg,self)
def __getattr__(self,aname):
if aname == "myException":
self.myException = ret = self.getException();
return ret;
else:
raise AttributeError("no such attribute " + aname)
def __eq__(self,other):
if isinstance(other, ParserElement):
return self is other or self.__dict__ == other.__dict__
elif isinstance(other, basestring):
try:
self.parseString(_ustr(other), parseAll=True)
return True
except ParseBaseException:
return False
else:
return super(ParserElement,self)==other
def __ne__(self,other):
return not (self == other)
def __hash__(self):
return hash(id(self))
def __req__(self,other):
return self == other
def __rne__(self,other):
return not (self == other)
class Token(ParserElement):
"""Abstract ParserElement subclass, for defining atomic matching patterns."""
def __init__( self ):
super(Token,self).__init__( savelist=False )
#self.myException = ParseException("",0,"",self)
def setName(self, name):
s = super(Token,self).setName(name)
self.errmsg = "Expected " + self.name
#s.myException.msg = self.errmsg
return s
class Empty(Token):
"""An empty token, will always match."""
def __init__( self ):
super(Empty,self).__init__()
self.name = "Empty"
self.mayReturnEmpty = True
self.mayIndexError = False
class NoMatch(Token):
"""A token that will never match."""
def __init__( self ):
super(NoMatch,self).__init__()
self.name = "NoMatch"
self.mayReturnEmpty = True
self.mayIndexError = False
self.errmsg = "Unmatchable token"
#self.myException.msg = self.errmsg
def parseImpl( self, instring, loc, doActions=True ):
exc = self.myException
exc.loc = loc
exc.pstr = instring
raise exc
class Literal(Token):
"""Token to exactly match a specified string."""
def __init__( self, matchString ):
super(Literal,self).__init__()
self.match = matchString
self.matchLen = len(matchString)
try:
self.firstMatchChar = matchString[0]
except IndexError:
warnings.warn("null string passed to Literal; use Empty() instead",
SyntaxWarning, stacklevel=2)
self.__class__ = Empty
self.name = '"%s"' % _ustr(self.match)
self.errmsg = "Expected " + self.name
self.mayReturnEmpty = False
#self.myException.msg = self.errmsg
self.mayIndexError = False
# Performance tuning: this routine gets called a *lot*
# if this is a single character match string and the first character matches,
# short-circuit as quickly as possible, and avoid calling startswith
#~ @profile
def parseImpl( self, instring, loc, doActions=True ):
if (instring[loc] == self.firstMatchChar and
(self.matchLen==1 or instring.startswith(self.match,loc)) ):
return loc+self.matchLen, self.match
#~ raise ParseException( instring, loc, self.errmsg )
exc = self.myException
exc.loc = loc
exc.pstr = instring
raise exc
_L = 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 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 "$"; caseless allows case-insensitive
matching, default is False.
"""
DEFAULT_KEYWORD_CHARS = alphanums+"_$"
def __init__( self, matchString, identChars=DEFAULT_KEYWORD_CHARS, caseless=False ):
super(Keyword,self).__init__()
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.myException.msg = self.errmsg
self.mayIndexError = False
self.caseless = caseless
if caseless:
self.caselessmatch = matchString.upper()
identChars = identChars.upper()
self.identChars = _str2dict(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 and
(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 )
exc = self.myException
exc.loc = loc
exc.pstr = instring
raise exc
def copy(self):
c = super(Keyword,self).copy()
c.identChars = Keyword.DEFAULT_KEYWORD_CHARS
return c
def setDefaultKeywordChars( chars ):
"""Overrides the default Keyword chars
"""
Keyword.DEFAULT_KEYWORD_CHARS = chars
setDefaultKeywordChars = staticmethod(setDefaultKeywordChars)
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.
"""
def __init__( self, matchString ):
super(CaselessLiteral,self).__init__( matchString.upper() )
# Preserve the defining literal.
self.returnString = matchString
self.name = "'%s'" % self.returnString
self.errmsg = "Expected " + self.name
#self.myException.msg = self.errmsg
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 )
exc = self.myException
exc.loc = loc
exc.pstr = instring
raise exc
class CaselessKeyword(Keyword):
def __init__( self, matchString, identChars=Keyword.DEFAULT_KEYWORD_CHARS ):
super(CaselessKeyword,self).__init__( matchString, identChars, caseless=True )
def parseImpl( self, instring, loc, doActions=True ):
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) ):
return loc+self.matchLen, self.match
#~ raise ParseException( instring, loc, self.errmsg )
exc = self.myException
exc.loc = loc
exc.pstr = instring
raise exc
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.
"""
def __init__( self, initChars, bodyChars=None, min=1, max=0, exact=0, asKeyword=False ):
super(Word,self).__init__()
self.initCharsOrig = initChars
self.initChars = _str2dict(initChars)
if bodyChars :
self.bodyCharsOrig = bodyChars
self.bodyChars = _str2dict(bodyChars)
else:
self.bodyCharsOrig = initChars
self.bodyChars = _str2dict(initChars)
self.maxSpecified = max > 0
if min < 1:
raise ValueError("cannot specify a minimum length < 1; use Optional(Word()) if zero-length word is permitted")
self.minLen = min
if max > 0:
self.maxLen = max
else:
self.maxLen = _MAX_INT
if exact > 0:
self.maxLen = exact
self.minLen = exact
self.name = _ustr(self)
self.errmsg = "Expected " + self.name
#self.myException.msg = self.errmsg
self.mayIndexError = False
self.asKeyword = asKeyword
if ' ' not in self.initCharsOrig+self.bodyCharsOrig and (min==1 and max==0 and exact==0):
if self.bodyCharsOrig == self.initCharsOrig:
self.reString = "[%s]+" % _escapeRegexRangeChars(self.initCharsOrig)
elif len(self.bodyCharsOrig) == 1:
self.reString = "%s[%s]*" % \
(re.escape(self.initCharsOrig),
_escapeRegexRangeChars(self.bodyCharsOrig),)
else:
self.reString = "[%s][%s]*" % \
(_escapeRegexRangeChars(self.initCharsOrig),
_escapeRegexRangeChars(self.bodyCharsOrig),)
if self.asKeyword:
self.reString = r"\b"+self.reString+r"\b"
try:
self.re = re.compile( self.reString )
except:
self.re = None
def parseImpl( self, instring, loc, doActions=True ):
if self.re:
result = self.re.match(instring,loc)
if not result:
exc = self.myException
exc.loc = loc
exc.pstr = instring
raise exc
loc = result.end()
return loc,result.group()
if not(instring[ loc ] in self.initChars):
#~ raise ParseException( instring, loc, self.errmsg )
exc = self.myException
exc.loc = loc
exc.pstr = instring
raise exc
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
if self.maxSpecified and loc < instrlen and instring[loc] in bodychars:
throwException = True
if 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 )
exc = self.myException
exc.loc = loc
exc.pstr = instring
raise exc
return loc, instring[start:loc]
def __str__( self ):
try:
return super(Word,self).__str__()
except:
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 Regex(Token):
"""Token for matching strings that match a given regular expression.
Defined with string specifying the regular expression in a form recognized by the inbuilt Python re module.
"""
def __init__( self, pattern, flags=0):
"""The parameters pattern and flags are passed to the re.compile() function as-is. See the Python re module for an explanation of the acceptable patterns and flags."""
super(Regex,self).__init__()
if len(pattern) == 0:
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
self.name = _ustr(self)
self.errmsg = "Expected " + self.name
#self.myException.msg = self.errmsg
self.mayIndexError = False
self.mayReturnEmpty = True
def parseImpl( self, instring, loc, doActions=True ):
result = self.re.match(instring,loc)
if not result:
exc = self.myException
exc.loc = loc
exc.pstr = instring
raise exc
loc = result.end()
d = result.groupdict()
ret = ParseResults(result.group())
if d:
for k in d:
ret[k] = d[k]
return loc,ret
def __str__( self ):
try:
return super(Regex,self).__str__()
except:
pass
if self.strRepr is None:
self.strRepr = "Re:(%s)" % repr(self.pattern)
return self.strRepr
class QuotedString(Token):
"""Token for matching strings that are delimited by quoting characters.
"""
def __init__( self, quoteChar, escChar=None, escQuote=None, multiline=False, unquoteResults=True, endQuoteChar=None):
"""
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)
"""
super(QuotedString,self).__init__()
# remove white space from quote chars - wont work anyway
quoteChar = quoteChar.strip()
if len(quoteChar) == 0:
warnings.warn("quoteChar cannot be the empty string",SyntaxWarning,stacklevel=2)
raise SyntaxError()
if endQuoteChar is None:
endQuoteChar = quoteChar
else:
endQuoteChar = endQuoteChar.strip()
if len(endQuoteChar) == 0:
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
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
except sre_constants.error:
warnings.warn("invalid pattern (%s) passed to Regex" % self.pattern,
SyntaxWarning, stacklevel=2)
raise
self.name = _ustr(self)
self.errmsg = "Expected " + self.name
#self.myException.msg = self.errmsg
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:
exc = self.myException
exc.loc = loc
exc.pstr = instring
raise exc
loc = result.end()
ret = result.group()
if self.unquoteResults:
# strip off quotes
ret = ret[self.quoteCharLen:-self.endQuoteCharLen]
if isinstance(ret,basestring):
# replace escaped characters
if self.escChar:
ret = re.sub(self.escCharReplacePattern,"\g<1>",ret)
# replace escaped quotes
if self.escQuote:
ret = ret.replace(self.escQuote, self.endQuoteChar)
return loc, ret
def __str__( self ):
try:
return super(QuotedString,self).__str__()
except:
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.
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.
"""
def __init__( self, notChars, min=1, max=0, exact=0 ):
super(CharsNotIn,self).__init__()
self.skipWhitespace = False
self.notChars = notChars
if min < 1:
raise ValueError("cannot specify a minimum length < 1; use Optional(CharsNotIn()) if zero-length char group is permitted")
self.minLen = min
if max > 0:
self.maxLen = max
else:
self.maxLen = _MAX_INT
if exact > 0:
self.maxLen = exact
self.minLen = exact
self.name = _ustr(self)
self.errmsg = "Expected " + self.name
self.mayReturnEmpty = ( self.minLen == 0 )
#self.myException.msg = self.errmsg
self.mayIndexError = False
def parseImpl( self, instring, loc, doActions=True ):
if instring[loc] in self.notChars:
#~ raise ParseException( instring, loc, self.errmsg )
exc = self.myException
exc.loc = loc
exc.pstr = instring
raise exc
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 )
exc = self.myException
exc.loc = loc
exc.pstr = instring
raise exc
return loc, instring[start:loc]
def __str__( self ):
try:
return super(CharsNotIn, self).__str__()
except:
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 Word class."""
whiteStrs = {
" " : "<SPC>",
"\t": "<TAB>",
"\n": "<LF>",
"\r": "<CR>",
"\f": "<FF>",
}
def __init__(self, ws=" \t\r\n", min=1, max=0, exact=0):
super(White,self).__init__()
self.matchWhite = ws
self.setWhitespaceChars( "".join([c for c in self.whiteChars if c not in self.matchWhite]) )
#~ self.leaveWhitespace()
self.name = ("".join([White.whiteStrs[c] for c in self.matchWhite]))
self.mayReturnEmpty = True
self.errmsg = "Expected " + self.name
#self.myException.msg = self.errmsg
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 not(instring[ loc ] in self.matchWhite):
#~ raise ParseException( instring, loc, self.errmsg )
exc = self.myException
exc.loc = loc
exc.pstr = instring
raise exc
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 )
exc = self.myException
exc.loc = loc
exc.pstr = instring
raise exc
return loc, instring[start:loc]
class _PositionToken(Token):
def __init__( self ):
super(_PositionToken,self).__init__()
self.name=self.__class__.__name__
self.mayReturnEmpty = True
self.mayIndexError = False
class GoToColumn(_PositionToken):
"""Token to advance to a specific column of input text; useful for tabular report scraping."""
def __init__( self, colno ):
super(GoToColumn,self).__init__()
self.col = colno
def preParse( self, instring, loc ):
if col(loc,instring) != self.col:
instrlen = len(instring)
if self.ignoreExprs:
loc = self._skipIgnorables( instring, loc )
while loc < instrlen and instring[loc].isspace() and col( loc, instring ) != self.col :
loc += 1
return loc
def parseImpl( self, instring, loc, doActions=True ):
thiscol = col( loc, instring )
if thiscol > self.col:
raise ParseException( instring, loc, "Text not in expected column", self )
newloc = loc + self.col - thiscol
ret = instring[ loc: newloc ]
return newloc, ret
class LineStart(_PositionToken):
"""Matches if current position is at the beginning of a line within the parse string"""
def __init__( self ):
super(LineStart,self).__init__()
self.setWhitespaceChars( ParserElement.DEFAULT_WHITE_CHARS.replace("\n","") )
self.errmsg = "Expected start of line"
#self.myException.msg = self.errmsg
def preParse( self, instring, loc ):
preloc = super(LineStart,self).preParse(instring,loc)
if instring[preloc] == "\n":
loc += 1
return loc
def parseImpl( self, instring, loc, doActions=True ):
if not( loc==0 or
(loc == self.preParse( instring, 0 )) or
(instring[loc-1] == "\n") ): #col(loc, instring) != 1:
#~ raise ParseException( instring, loc, "Expected start of line" )
exc = self.myException
exc.loc = loc
exc.pstr = instring
raise exc
return loc, []
class LineEnd(_PositionToken):
"""Matches if current position is at the end of a line within the parse string"""
def __init__( self ):
super(LineEnd,self).__init__()
self.setWhitespaceChars( ParserElement.DEFAULT_WHITE_CHARS.replace("\n","") )
self.errmsg = "Expected end of line"
#self.myException.msg = self.errmsg
def parseImpl( self, instring, loc, doActions=True ):
if loc<len(instring):
if instring[loc] == "\n":
return loc+1, "\n"
else:
#~ raise ParseException( instring, loc, "Expected end of line" )
exc = self.myException
exc.loc = loc
exc.pstr = instring
raise exc
elif loc == len(instring):
return loc+1, []
else:
exc = self.myException
exc.loc = loc
exc.pstr = instring
raise exc
class StringStart(_PositionToken):
"""Matches if current position is at the beginning of the parse string"""
def __init__( self ):
super(StringStart,self).__init__()
self.errmsg = "Expected start of text"
#self.myException.msg = self.errmsg
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, "Expected start of text" )
exc = self.myException
exc.loc = loc
exc.pstr = instring
raise exc
return loc, []
class StringEnd(_PositionToken):
"""Matches if current position is at the end of the parse string"""
def __init__( self ):
super(StringEnd,self).__init__()
self.errmsg = "Expected end of text"
#self.myException.msg = self.errmsg
def parseImpl( self, instring, loc, doActions=True ):
if loc < len(instring):
#~ raise ParseException( instring, loc, "Expected end of text" )
exc = self.myException
exc.loc = loc
exc.pstr = instring
raise exc
elif loc == len(instring):
return loc+1, []
elif loc > len(instring):
return loc, []
else:
exc = self.myException
exc.loc = loc
exc.pstr = instring
raise exc
class WordStart(_PositionToken):
"""Matches if the current position is at the beginning of a Word, and
is not preceded by any character in a given set of wordChars
(default=printables). To emulate the \b behavior of regular expressions,
use WordStart(alphanums). WordStart will also match at the beginning of
the string being parsed, or at the beginning of a line.
"""
def __init__(self, wordChars = printables):
super(WordStart,self).__init__()
self.wordChars = _str2dict(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):
exc = self.myException
exc.loc = loc
exc.pstr = instring
raise exc
return loc, []
class WordEnd(_PositionToken):
"""Matches if the current position is at the end of a Word, and
is not followed by any character in a given set of wordChars
(default=printables). To emulate the \b behavior of regular expressions,
use WordEnd(alphanums). WordEnd will also match at the end of
the string being parsed, or at the end of a line.
"""
def __init__(self, wordChars = printables):
super(WordEnd,self).__init__()
self.wordChars = _str2dict(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, "Expected end of word" )
exc = self.myException
exc.loc = loc
exc.pstr = instring
raise exc
return loc, []
class ParseExpression(ParserElement):
"""Abstract subclass of ParserElement, for combining and post-processing parsed tokens."""
def __init__( self, exprs, savelist = False ):
super(ParseExpression,self).__init__(savelist)
if isinstance( exprs, list ):
self.exprs = exprs
elif isinstance( exprs, basestring ):
self.exprs = [ Literal( exprs ) ]
else:
try:
self.exprs = list( exprs )
except TypeError:
self.exprs = [ exprs ]
self.callPreparse = False
def __getitem__( self, i ):
return self.exprs[i]
def append( self, other ):
self.exprs.append( other )
self.strRepr = None
return self
def leaveWhitespace( self ):
"""Extends leaveWhitespace defined in base class, and also invokes leaveWhitespace on
all contained expressions."""
self.skipWhitespace = False
self.exprs = [ e.copy() for e in self.exprs ]
for e in self.exprs:
e.leaveWhitespace()
return self
def ignore( self, other ):
if isinstance( other, Suppress ):
if other not in self.ignoreExprs:
super( ParseExpression, self).ignore( other )
for e in self.exprs:
e.ignore( self.ignoreExprs[-1] )
else:
super( ParseExpression, self).ignore( other )
for e in self.exprs:
e.ignore( self.ignoreExprs[-1] )
return self
def __str__( self ):
try:
return super(ParseExpression,self).__str__()
except:
pass
if self.strRepr is None:
self.strRepr = "%s:(%s)" % ( self.__class__.__name__, _ustr(self.exprs) )
return self.strRepr
def streamline( self ):
super(ParseExpression,self).streamline()
for e in self.exprs:
e.streamline()
# collapse nested And's of the form And( And( And( a,b), c), d) to And( a,b,c,d )
# but only if there are no parse actions or resultsNames on the nested And's
# (likewise for Or's and MatchFirst's)
if ( len(self.exprs) == 2 ):
other = self.exprs[0]
if ( isinstance( other, self.__class__ ) and
not(other.parseAction) and
other.resultsName is None and
not other.debug ):
self.exprs = other.exprs[:] + [ self.exprs[1] ]
self.strRepr = None
self.mayReturnEmpty |= other.mayReturnEmpty
self.mayIndexError |= other.mayIndexError
other = self.exprs[-1]
if ( isinstance( other, self.__class__ ) and
not(other.parseAction) and
other.resultsName is None and
not other.debug ):
self.exprs = self.exprs[:-1] + other.exprs[:]
self.strRepr = None
self.mayReturnEmpty |= other.mayReturnEmpty
self.mayIndexError |= other.mayIndexError
return self
def setResultsName( self, name, listAllMatches=False ):
ret = super(ParseExpression,self).setResultsName(name,listAllMatches)
return ret
def validate( self, validateTrace=[] ):
tmp = validateTrace[:]+[self]
for e in self.exprs:
e.validate(tmp)
self.checkRecursion( [] )
class And(ParseExpression):
"""Requires all given ParseExpressions to be found in the given order.
Expressions may be separated by whitespace.
May be constructed using the '+' operator.
"""
class _ErrorStop(Empty):
def __init__(self, *args, **kwargs):
super(Empty,self).__init__(*args, **kwargs)
self.leaveWhitespace()
def __init__( self, exprs, savelist = True ):
super(And,self).__init__(exprs, savelist)
self.mayReturnEmpty = True
for e in self.exprs:
if not e.mayReturnEmpty:
self.mayReturnEmpty = False
break
self.setWhitespaceChars( exprs[0].whiteChars )
self.skipWhitespace = exprs[0].skipWhitespace
self.callPreparse = True
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, pe:
raise ParseSyntaxException(pe)
except IndexError, ie:
raise ParseSyntaxException( ParseException(instring, len(instring), self.errmsg, self) )
else:
loc, exprtokens = e._parse( instring, loc, doActions )
if exprtokens or exprtokens.keys():
resultlist += exprtokens
return loc, resultlist
def __iadd__(self, other ):
if isinstance( other, basestring ):
other = Literal( other )
return self.append( other ) #And( [ self, other ] )
def checkRecursion( self, parseElementList ):
subRecCheckList = parseElementList[:] + [ self ]
for e in self.exprs:
e.checkRecursion( subRecCheckList )
if not e.mayReturnEmpty:
break
def __str__( self ):
if hasattr(self,"name"):
return self.name
if self.strRepr is None:
self.strRepr = "{" + " ".join( [ _ustr(e) for e in self.exprs ] ) + "}"
return self.strRepr
class Or(ParseExpression):
"""Requires that at least one ParseExpression is found.
If two expressions match, the expression that matches the longest string will be used.
May be constructed using the '^' operator.
"""
def __init__( self, exprs, savelist = False ):
super(Or,self).__init__(exprs, savelist)
self.mayReturnEmpty = False
for e in self.exprs:
if e.mayReturnEmpty:
self.mayReturnEmpty = True
break
def parseImpl( self, instring, loc, doActions=True ):
maxExcLoc = -1
maxMatchLoc = -1
maxException = None
for e in self.exprs:
try:
loc2 = e.tryParse( instring, loc )
except ParseException, err:
if err.loc > maxExcLoc:
maxException = err
maxExcLoc = err.loc
except IndexError:
if len(instring) > maxExcLoc:
maxException = ParseException(instring,len(instring),e.errmsg,self)
maxExcLoc = len(instring)
else:
if loc2 > maxMatchLoc:
maxMatchLoc = loc2
maxMatchExp = e
if maxMatchLoc < 0:
if maxException is not None:
raise maxException
else:
raise ParseException(instring, loc, "no defined alternatives to match", self)
return maxMatchExp._parse( instring, loc, doActions )
def __ixor__(self, other ):
if isinstance( other, basestring ):
other = Literal( other )
return self.append( other ) #Or( [ self, other ] )
def __str__( self ):
if hasattr(self,"name"):
return self.name
if self.strRepr is None:
self.strRepr = "{" + " ^ ".join( [ _ustr(e) for e in self.exprs ] ) + "}"
return self.strRepr
def checkRecursion( self, parseElementList ):
subRecCheckList = parseElementList[:] + [ self ]
for e in self.exprs:
e.checkRecursion( subRecCheckList )
class MatchFirst(ParseExpression):
"""Requires that at least one ParseExpression is found.
If two expressions match, the first one listed is the one that will match.
May be constructed using the '|' operator.
"""
def __init__( self, exprs, savelist = False ):
super(MatchFirst,self).__init__(exprs, savelist)
if exprs:
self.mayReturnEmpty = False
for e in self.exprs:
if e.mayReturnEmpty:
self.mayReturnEmpty = True
break
else:
self.mayReturnEmpty = True
def parseImpl( self, instring, loc, doActions=True ):
maxExcLoc = -1
maxException = None
for e in self.exprs:
try:
ret = e._parse( instring, loc, doActions )
return ret
except ParseException, err:
if err.loc > maxExcLoc:
maxException = err
maxExcLoc = err.loc
except IndexError:
if len(instring) > maxExcLoc:
maxException = ParseException(instring,len(instring),e.errmsg,self)
maxExcLoc = len(instring)
# only got here if no expression matched, raise exception for match that made it the furthest
else:
if maxException is not None:
raise maxException
else:
raise ParseException(instring, loc, "no defined alternatives to match", self)
def __ior__(self, other ):
if isinstance( other, basestring ):
other = Literal( other )
return self.append( other ) #MatchFirst( [ self, other ] )
def __str__( self ):
if hasattr(self,"name"):
return self.name
if self.strRepr is None:
self.strRepr = "{" + " | ".join( [ _ustr(e) for e in self.exprs ] ) + "}"
return self.strRepr
def checkRecursion( self, parseElementList ):
subRecCheckList = parseElementList[:] + [ self ]
for e in self.exprs:
e.checkRecursion( subRecCheckList )
class Each(ParseExpression):
"""Requires all given ParseExpressions to be found, but in any order.
Expressions may be separated by whitespace.
May be constructed using the '&' operator.
"""
def __init__( self, exprs, savelist = True ):
super(Each,self).__init__(exprs, savelist)
self.mayReturnEmpty = True
for e in self.exprs:
if not e.mayReturnEmpty:
self.mayReturnEmpty = False
break
self.skipWhitespace = True
self.initExprGroups = True
def parseImpl( self, instring, loc, doActions=True ):
if self.initExprGroups:
self.optionals = [ e.expr for e in self.exprs if isinstance(e,Optional) ]
self.multioptionals = [ e.expr for e in self.exprs if isinstance(e,ZeroOrMore) ]
self.multirequired = [ e.expr for e in self.exprs if isinstance(e,OneOrMore) ]
self.required = [ e for e in self.exprs if not isinstance(e,(Optional,ZeroOrMore,OneOrMore)) ]
self.required += self.multirequired
self.initExprGroups = False
tmpLoc = loc
tmpReqd = self.required[:]
tmpOpt = self.optionals[:]
matchOrder = []
keepMatching = True
while keepMatching:
tmpExprs = tmpReqd + tmpOpt + self.multioptionals + self.multirequired
failed = []
for e in tmpExprs:
try:
tmpLoc = e.tryParse( instring, tmpLoc )
except ParseException:
failed.append(e)
else:
matchOrder.append(e)
if e in tmpReqd:
tmpReqd.remove(e)
elif e in tmpOpt:
tmpOpt.remove(e)
if len(failed) == len(tmpExprs):
keepMatching = False
if tmpReqd:
missing = ", ".join( [ _ustr(e) for e in tmpReqd ] )
raise ParseException(instring,loc,"Missing one or more required elements (%s)" % missing )
# add any unmatched Optionals, in case they have default values defined
matchOrder += list(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 = ParseResults([])
for r in resultlist:
dups = {}
for k in r.keys():
if k in finalResults.keys():
tmp = ParseResults(finalResults[k])
tmp += ParseResults(r[k])
dups[k] = tmp
finalResults += ParseResults(r)
for k,v in dups.items():
finalResults[k] = v
return loc, finalResults
def __str__( self ):
if hasattr(self,"name"):
return self.name
if self.strRepr is None:
self.strRepr = "{" + " & ".join( [ _ustr(e) for e in self.exprs ] ) + "}"
return self.strRepr
def checkRecursion( self, parseElementList ):
subRecCheckList = parseElementList[:] + [ self ]
for e in self.exprs:
e.checkRecursion( subRecCheckList )
class ParseElementEnhance(ParserElement):
"""Abstract subclass of ParserElement, for combining and post-processing parsed tokens."""
def __init__( self, expr, savelist=False ):
super(ParseElementEnhance,self).__init__(savelist)
if isinstance( expr, basestring ):
expr = Literal(expr)
self.expr = expr
self.strRepr = None
if expr is not None:
self.mayIndexError = expr.mayIndexError
self.mayReturnEmpty = expr.mayReturnEmpty
self.setWhitespaceChars( expr.whiteChars )
self.skipWhitespace = expr.skipWhitespace
self.saveAsList = expr.saveAsList
self.callPreparse = expr.callPreparse
self.ignoreExprs.extend(expr.ignoreExprs)
def parseImpl( self, instring, loc, doActions=True ):
if self.expr is not None:
return self.expr._parse( instring, loc, doActions, callPreParse=False )
else:
raise ParseException("",loc,self.errmsg,self)
def leaveWhitespace( self ):
self.skipWhitespace = False
self.expr = self.expr.copy()
if self.expr is not None:
self.expr.leaveWhitespace()
return self
def ignore( self, other ):
if isinstance( other, Suppress ):
if other not in self.ignoreExprs:
super( ParseElementEnhance, self).ignore( other )
if self.expr is not None:
self.expr.ignore( self.ignoreExprs[-1] )
else:
super( ParseElementEnhance, self).ignore( other )
if self.expr is not None:
self.expr.ignore( self.ignoreExprs[-1] )
return self
def streamline( self ):
super(ParseElementEnhance,self).streamline()
if self.expr is not None:
self.expr.streamline()
return self
def checkRecursion( self, parseElementList ):
if self in parseElementList:
raise RecursiveGrammarException( parseElementList+[self] )
subRecCheckList = parseElementList[:] + [ self ]
if self.expr is not None:
self.expr.checkRecursion( subRecCheckList )
def validate( self, validateTrace=[] ):
tmp = validateTrace[:]+[self]
if self.expr is not None:
self.expr.validate(tmp)
self.checkRecursion( [] )
def __str__( self ):
try:
return super(ParseElementEnhance,self).__str__()
except:
pass
if self.strRepr is None and self.expr is not None:
self.strRepr = "%s:(%s)" % ( self.__class__.__name__, _ustr(self.expr) )
return self.strRepr
class FollowedBy(ParseElementEnhance):
"""Lookahead matching of the given parse expression. FollowedBy
does *not* advance the parsing position within the input string, it only
verifies that the specified parse expression matches at the current
position. FollowedBy always returns a null token list."""
def __init__( self, expr ):
super(FollowedBy,self).__init__(expr)
self.mayReturnEmpty = True
def parseImpl( self, instring, loc, doActions=True ):
self.expr.tryParse( instring, loc )
return loc, []
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."""
def __init__( self, expr ):
super(NotAny,self).__init__(expr)
#~ self.leaveWhitespace()
self.skipWhitespace = False # do NOT use self.leaveWhitespace(), don't want to propagate to exprs
self.mayReturnEmpty = True
self.errmsg = "Found unwanted token, "+_ustr(self.expr)
#self.myException = ParseException("",0,self.errmsg,self)
def parseImpl( self, instring, loc, doActions=True ):
try:
self.expr.tryParse( instring, loc )
except (ParseException,IndexError):
pass
else:
#~ raise ParseException(instring, loc, self.errmsg )
exc = self.myException
exc.loc = loc
exc.pstr = instring
raise exc
return loc, []
def __str__( self ):
if hasattr(self,"name"):
return self.name
if self.strRepr is None:
self.strRepr = "~{" + _ustr(self.expr) + "}"
return self.strRepr
class ZeroOrMore(ParseElementEnhance):
"""Optional repetition of zero or more of the given expression."""
def __init__( self, expr ):
super(ZeroOrMore,self).__init__(expr)
self.mayReturnEmpty = True
def parseImpl( self, instring, loc, doActions=True ):
tokens = []
try:
loc, tokens = self.expr._parse( instring, loc, doActions, callPreParse=False )
hasIgnoreExprs = ( len(self.ignoreExprs) > 0 )
while 1:
if hasIgnoreExprs:
preloc = self._skipIgnorables( instring, loc )
else:
preloc = loc
loc, tmptokens = self.expr._parse( instring, preloc, doActions )
if tmptokens or tmptokens.keys():
tokens += tmptokens
except (ParseException,IndexError):
pass
return loc, tokens
def __str__( self ):
if hasattr(self,"name"):
return self.name
if self.strRepr is None:
self.strRepr = "[" + _ustr(self.expr) + "]..."
return self.strRepr
def setResultsName( self, name, listAllMatches=False ):
ret = super(ZeroOrMore,self).setResultsName(name,listAllMatches)
ret.saveAsList = True
return ret
class OneOrMore(ParseElementEnhance):
"""Repetition of one or more of the given expression."""
def parseImpl( self, instring, loc, doActions=True ):
# must be at least one
loc, tokens = self.expr._parse( instring, loc, doActions, callPreParse=False )
try:
hasIgnoreExprs = ( len(self.ignoreExprs) > 0 )
while 1:
if hasIgnoreExprs:
preloc = self._skipIgnorables( instring, loc )
else:
preloc = loc
loc, tmptokens = self.expr._parse( instring, preloc, doActions )
if tmptokens or tmptokens.keys():
tokens += tmptokens
except (ParseException,IndexError):
pass
return loc, tokens
def __str__( self ):
if hasattr(self,"name"):
return self.name
if self.strRepr is None:
self.strRepr = "{" + _ustr(self.expr) + "}..."
return self.strRepr
def setResultsName( self, name, listAllMatches=False ):
ret = super(OneOrMore,self).setResultsName(name,listAllMatches)
ret.saveAsList = True
return ret
class _NullToken(object):
def __bool__(self):
return False
__nonzero__ = __bool__
def __str__(self):
return ""
_optionalNotMatched = _NullToken()
class Optional(ParseElementEnhance):
"""Optional matching of the given expression.
A default return string can also be specified, if the optional expression
is not found.
"""
def __init__( self, exprs, default=_optionalNotMatched ):
super(Optional,self).__init__( exprs, savelist=False )
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 _optionalNotMatched:
if self.expr.resultsName:
tokens = ParseResults([ self.defaultValue ])
tokens[self.expr.resultsName] = self.defaultValue
else:
tokens = [ self.defaultValue ]
else:
tokens = []
return loc, tokens
def __str__( self ):
if hasattr(self,"name"):
return self.name
if self.strRepr is None:
self.strRepr = "[" + _ustr(self.expr) + "]"
return self.strRepr
class SkipTo(ParseElementEnhance):
"""Token for skipping over all undefined text until the matched expression is found.
If include is set to true, the matched expression is also parsed (the skipped text
and matched expression are returned as a 2-element list). The ignore
argument is used to define grammars (typically quoted strings and comments) that
might contain false matches.
"""
def __init__( self, other, include=False, ignore=None, failOn=None ):
super( SkipTo, self ).__init__( other )
self.ignoreExpr = ignore
self.mayReturnEmpty = True
self.mayIndexError = False
self.includeMatch = include
self.asList = False
if failOn is not None and isinstance(failOn, basestring):
self.failOn = Literal(failOn)
else:
self.failOn = failOn
self.errmsg = "No match found for "+_ustr(self.expr)
#self.myException = ParseException("",0,self.errmsg,self)
def parseImpl( self, instring, loc, doActions=True ):
startLoc = loc
instrlen = len(instring)
expr = self.expr
failParse = False
while loc <= instrlen:
try:
if self.failOn:
try:
self.failOn.tryParse(instring, loc)
except ParseBaseException:
pass
else:
failParse = True
raise ParseException(instring, loc, "Found expression " + str(self.failOn))
failParse = False
if self.ignoreExpr is not None:
while 1:
try:
loc = self.ignoreExpr.tryParse(instring,loc)
print "found ignoreExpr, advance to", loc
except ParseBaseException:
break
expr._parse( instring, loc, doActions=False, callPreParse=False )
skipText = instring[startLoc:loc]
if self.includeMatch:
loc,mat = expr._parse(instring,loc,doActions,callPreParse=False)
if mat:
skipRes = ParseResults( skipText )
skipRes += mat
return loc, [ skipRes ]
else:
return loc, [ skipText ]
else:
return loc, [ skipText ]
except (ParseException,IndexError):
if failParse:
raise
else:
loc += 1
exc = self.myException
exc.loc = loc
exc.pstr = instring
raise exc
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)
"""
def __init__( self, other=None ):
super(Forward,self).__init__( other, savelist=False )
def __lshift__( self, other ):
if isinstance( other, basestring ):
other = Literal(other)
self.expr = other
self.mayReturnEmpty = other.mayReturnEmpty
self.strRepr = None
self.mayIndexError = self.expr.mayIndexError
self.mayReturnEmpty = self.expr.mayReturnEmpty
self.setWhitespaceChars( self.expr.whiteChars )
self.skipWhitespace = self.expr.skipWhitespace
self.saveAsList = self.expr.saveAsList
self.ignoreExprs.extend(self.expr.ignoreExprs)
return None
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=[] ):
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
self._revertClass = self.__class__
self.__class__ = _ForwardNoRecurse
try:
if self.expr is not None:
retString = _ustr(self.expr)
else:
retString = "None"
finally:
self.__class__ = self._revertClass
return self.__class__.__name__ + ": " + retString
def copy(self):
if self.expr is not None:
return super(Forward,self).copy()
else:
ret = Forward()
ret << self
return ret
class _ForwardNoRecurse(Forward):
def __str__( self ):
return "..."
class TokenConverter(ParseElementEnhance):
"""Abstract subclass of ParseExpression, for converting parsed results."""
def __init__( self, expr, savelist=False ):
super(TokenConverter,self).__init__( expr )#, savelist )
self.saveAsList = False
class Upcase(TokenConverter):
"""Converter to upper case all matching tokens."""
def __init__(self, *args):
super(Upcase,self).__init__(*args)
warnings.warn("Upcase class is deprecated, use upcaseTokens parse action instead",
DeprecationWarning,stacklevel=2)
def postParse( self, instring, loc, tokenlist ):
return list(map( string.upper, tokenlist ))
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.
"""
def __init__( self, expr, joinString="", adjacent=True ):
super(Combine,self).__init__( expr )
# suppress whitespace-stripping in contained parse expressions, but re-enable it on the Combine itself
if adjacent:
self.leaveWhitespace()
self.adjacent = adjacent
self.skipWhitespace = True
self.joinString = joinString
def ignore( self, other ):
if self.adjacent:
ParserElement.ignore(self, other)
else:
super( Combine, self).ignore( other )
return self
def postParse( self, instring, loc, tokenlist ):
retToks = tokenlist.copy()
del retToks[:]
retToks += ParseResults([ "".join(tokenlist._asStringList(self.joinString)) ], modal=self.modalResults)
if self.resultsName and len(retToks.keys())>0:
return [ retToks ]
else:
return retToks
class Group(TokenConverter):
"""Converter to return the matched tokens as a list - useful for returning tokens of ZeroOrMore and OneOrMore expressions."""
def __init__( self, expr ):
super(Group,self).__init__( expr )
self.saveAsList = True
def postParse( self, instring, loc, tokenlist ):
return [ tokenlist ]
class Dict(TokenConverter):
"""Converter to return a repetitive expression as a list, but also as a dictionary.
Each element can also be referenced using the first token in the expression as its key.
Useful for tabular report scraping when the first column can be used as a item key.
"""
def __init__( self, exprs ):
super(Dict,self).__init__( exprs )
self.saveAsList = True
def postParse( self, instring, loc, tokenlist ):
for i,tok in enumerate(tokenlist):
if len(tok) == 0:
continue
ikey = tok[0]
if isinstance(ikey,int):
ikey = _ustr(tok[0]).strip()
if len(tok)==1:
tokenlist[ikey] = _ParseResultsWithOffset("",i)
elif len(tok)==2 and not isinstance(tok[1],ParseResults):
tokenlist[ikey] = _ParseResultsWithOffset(tok[1],i)
else:
dictvalue = tok.copy() #ParseResults(i)
del dictvalue[0]
if len(dictvalue)!= 1 or (isinstance(dictvalue,ParseResults) and dictvalue.keys()):
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."""
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 = ParserElement._normalizeParseActionArgs(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."""
f = ParserElement._normalizeParseActionArgs(f)
def z(*paArgs):
thisFunc = f.func_name
s,l,t = paArgs[-3:]
if len(paArgs)>3:
thisFunc = paArgs[0].__class__.__name__ + '.' + thisFunc
sys.stderr.write( ">>entering %s(line: '%s', %d, %s)\n" % (thisFunc,line(l,s),l,t) )
try:
ret = f(*paArgs)
except Exception, exc:
sys.stderr.write( "<<leaving %s (exception: %s)\n" % (thisFunc,exc) )
raise
sys.stderr.write( "<<leaving %s (ret: %s)\n" % (thisFunc,ret) )
return ret
try:
z.__name__ = f.__name__
except AttributeError:
pass
return z
#
# global helpers
#
def delimitedList( expr, delim=",", combine=False ):
"""Helper to define a delimited list of expressions - the delimiter defaults to ','.
By default, the list elements and delimiters can have intervening whitespace, and
comments, but this can be overridden by passing 'combine=True' in the constructor.
If combine is set to True, the matching tokens are returned as a single token
string, with the delimiters included; otherwise, the matching tokens are returned
as a list of tokens, with the delimiters suppressed.
"""
dlName = _ustr(expr)+" ["+_ustr(delim)+" "+_ustr(expr)+"]..."
if combine:
return Combine( expr + ZeroOrMore( delim + expr ) ).setName(dlName)
else:
return ( expr + ZeroOrMore( Suppress( delim ) + expr ) ).setName(dlName)
def countedArray( expr ):
"""Helper to define a counted list of expressions.
This helper defines a pattern of the form::
integer expr expr expr...
where the leading integer tells how many expr expressions follow.
The matched tokens returns the array of expr tokens as a list - the leading count token is suppressed.
"""
arrayExpr = Forward()
def countFieldParseAction(s,l,t):
n = int(t[0])
arrayExpr << (n and Group(And([expr]*n)) or Group(empty))
return []
return ( Word(nums).setName("arrayLen").setParseAction(countFieldParseAction, callDuringTry=True) + arrayExpr )
def _flatten(L):
if type(L) is not list: return [L]
if L == []: return L
return _flatten(L[0]) + _flatten(L[1:])
def matchPreviousLiteral(expr):
"""Helper to define an expression that is indirectly defined from
the tokens matched in a previous expression, that is, it looks
for a 'repeat' of a previous expression. For example::
first = Word(nums)
second = matchPreviousLiteral(first)
matchExpr = first + ":" + second
will match "1:1", but not "1:2". Because this matches a
previous literal, will also match the leading "1:1" in "1:10".
If this is not desired, use matchPreviousExpr.
Do *not* use with packrat parsing enabled.
"""
rep = Forward()
def copyTokenToRepeater(s,l,t):
if t:
if len(t) == 1:
rep << t[0]
else:
# flatten t tokens
tflat = _flatten(t.asList())
rep << And( [ Literal(tt) for tt in tflat ] )
else:
rep << Empty()
expr.addParseAction(copyTokenToRepeater, callDuringTry=True)
return rep
def matchPreviousExpr(expr):
"""Helper to define an expression that is indirectly defined from
the tokens matched in a previous expression, that is, it looks
for a 'repeat' of a previous expression. For example::
first = Word(nums)
second = matchPreviousExpr(first)
matchExpr = first + ":" + second
will match "1:1", but not "1:2". Because this matches by
expressions, will *not* match the leading "1:1" in "1:10";
the expressions are evaluated first, and then compared, so
"1" is compared with "10".
Do *not* use with packrat parsing enabled.
"""
rep = Forward()
e2 = expr.copy()
rep << e2
def copyTokenToRepeater(s,l,t):
matchTokens = _flatten(t.asList())
def mustMatchTheseTokens(s,l,t):
theseTokens = _flatten(t.asList())
if theseTokens != matchTokens:
raise ParseException("",0,"")
rep.setParseAction( mustMatchTheseTokens, callDuringTry=True )
expr.addParseAction(copyTokenToRepeater, callDuringTry=True)
return rep
def _escapeRegexRangeChars(s):
#~ escape these chars: ^-]
for c in r"\^-]":
s = s.replace(c,_bslash+c)
s = s.replace("\n",r"\n")
s = s.replace("\t",r"\t")
return _ustr(s)
def oneOf( strs, caseless=False, useRegex=True ):
"""Helper to quickly define a set of alternative Literals, and makes sure to do
longest-first testing when there is a conflict, regardless of the input order,
but returns a MatchFirst for best performance.
Parameters:
- strs - a string of space-delimited literals, or a list of string literals
- caseless - (default=False) - treat all literals as caseless
- useRegex - (default=True) - as an optimization, will generate a Regex
object; otherwise, will generate a MatchFirst object (if caseless=True, or
if creating a Regex raises an exception)
"""
if caseless:
isequal = ( lambda a,b: a.upper() == b.upper() )
masks = ( lambda a,b: b.upper().startswith(a.upper()) )
parseElementClass = CaselessLiteral
else:
isequal = ( lambda a,b: a == b )
masks = ( lambda a,b: b.startswith(a) )
parseElementClass = Literal
if isinstance(strs,(list,tuple)):
symbols = list(strs[:])
elif isinstance(strs,basestring):
symbols = strs.split()
else:
warnings.warn("Invalid argument to oneOf, expected string or list",
SyntaxWarning, stacklevel=2)
i = 0
while i < len(symbols)-1:
cur = symbols[i]
for j,other in enumerate(symbols[i+1:]):
if ( isequal(other, cur) ):
del symbols[i+j+1]
break
elif ( masks(cur, other) ):
del symbols[i+j+1]
symbols.insert(i,other)
cur = other
break
else:
i += 1
if not caseless and useRegex:
#~ print (strs,"->", "|".join( [ _escapeRegexChars(sym) for sym in symbols] ))
try:
if len(symbols)==len("".join(symbols)):
return Regex( "[%s]" % "".join( [ _escapeRegexRangeChars(sym) for sym in symbols] ) )
else:
return Regex( "|".join( [ re.escape(sym) for sym in symbols] ) )
except:
warnings.warn("Exception creating Regex for oneOf, building MatchFirst",
SyntaxWarning, stacklevel=2)
# last resort, just use MatchFirst
return MatchFirst( [ parseElementClass(sym) for sym in symbols ] )
def dictOf( key, value ):
"""Helper to easily and clearly define a dictionary by specifying the respective patterns
for the key and value. Takes care of defining the Dict, ZeroOrMore, and Group tokens
in the proper order. The key pattern can include delimiting markers or punctuation,
as long as they are suppressed, thereby leaving the significant key text. The value
pattern can include named results, so that the Dict results can include named token
fields.
"""
return Dict( ZeroOrMore( Group ( key + value ) ) )
def originalTextFor(expr, asString=True):
"""Helper to return the original, untokenized text for a given expression. Useful to
restore the parsed fields of an HTML start tag into the raw tag text itself, or to
revert separate tokens with intervening whitespace back to the original matching
input text. Simpler to use than the parse action keepOriginalText, and does not
require the inspect module to chase up the call stack. By default, returns a
string containing the original parsed text.
If the optional asString argument is passed as False, then the return value is a
ParseResults containing any results names that were originally matched, and a
single token containing the original matched text from the input string. So if
the expression passed to originalTextFor contains expressions with defined
results names, you must set asString to False if you want to preserve those
results name values."""
locMarker = Empty().setParseAction(lambda s,loc,t: loc)
matchExpr = locMarker("_original_start") + expr + locMarker("_original_end")
if asString:
extractText = lambda s,l,t: s[t._original_start:t._original_end]
else:
def extractText(s,l,t):
del t[:]
t.insert(0, s[t._original_start:t._original_end])
del t["_original_start"]
del t["_original_end"]
matchExpr.setParseAction(extractText)
return matchExpr
# 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"\[]-*.$+^?()~ ", exact=2 ).setParseAction(lambda s,l,t:t[0][1])
_printables_less_backslash = "".join([ c for c in printables if c not in r"\]" ])
_escapedHexChar = Combine( Suppress(_bslash + "0x") + Word(hexnums) ).setParseAction(lambda s,l,t:unichr(int(t[0],16)))
_escapedOctChar = Combine( Suppress(_bslash) + Word("0","01234567") ).setParseAction(lambda s,l,t:unichr(int(t[0],8)))
_singleChar = _escapedPunc | _escapedHexChar | _escapedOctChar | Word(_printables_less_backslash,exact=1)
_charRange = Group(_singleChar + Suppress("-") + _singleChar)
_reBracketExpr = Literal("[") + Optional("^").setResultsName("negate") + Group( OneOrMore( _charRange | _singleChar ) ).setResultsName("body") + "]"
_expanded = lambda p: (isinstance(p,ParseResults) and ''.join([ unichr(c) for c in range(ord(p[0]),ord(p[1])+1) ]) or p)
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 '\0x' (\0x21, which is a '!' character)
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.)
"""
try:
return "".join([_expanded(part) for part in _reBracketExpr.parseString(s).body])
except:
return ""
def matchOnlyAtCol(n):
"""Helper method for defining parse actions that require matching at a specific
column in the input text.
"""
def verifyCol(strg,locn,toks):
if col(locn,strg) != n:
raise ParseException(strg,locn,"matched token not at column %d" % n)
return verifyCol
def replaceWith(replStr):
"""Helper method for common parse actions that simply return a literal value. Especially
useful when used with transformString().
"""
def _replFunc(*args):
return [replStr]
return _replFunc
def removeQuotes(s,l,t):
"""Helper parse action for removing quotation marks from parsed quoted strings.
To use, add this parse action to quoted string using::
quotedString.setParseAction( removeQuotes )
"""
return t[0][1:-1]
def upcaseTokens(s,l,t):
"""Helper parse action to convert tokens to upper case."""
return [ tt.upper() for tt in map(_ustr,t) ]
def downcaseTokens(s,l,t):
"""Helper parse action to convert tokens to lower case."""
return [ tt.lower() for tt in map(_ustr,t) ]
def keepOriginalText(s,startLoc,t):
"""Helper parse action to preserve original parsed text,
overriding any nested parse actions."""
try:
endloc = getTokensEndLoc()
except ParseException:
raise ParseFatalException("incorrect usage of keepOriginalText - may only be called as a parse action")
del t[:]
t += ParseResults(s[startLoc:endloc])
return t
def getTokensEndLoc():
"""Method to be called from within a parse action to determine the end
location of the parsed tokens."""
import inspect
fstack = inspect.stack()
try:
# search up the stack (through intervening argument normalizers) for correct calling routine
for f in fstack[2:]:
if f[3] == "_parseNoCache":
endloc = f[0].f_locals["loc"]
return endloc
else:
raise ParseFatalException("incorrect usage of getTokensEndLoc - may only be called from within a parse action")
finally:
del fstack
def _makeTags(tagStr, xml):
"""Internal helper to construct opening and closing tag expressions, given a tag name"""
if isinstance(tagStr,basestring):
resname = tagStr
tagStr = Keyword(tagStr, caseless=not xml)
else:
resname = tagStr.name
tagAttrName = Word(alphas,alphanums+"_-:")
if (xml):
tagAttrValue = dblQuotedString.copy().setParseAction( removeQuotes )
openTag = Suppress("<") + tagStr + \
Dict(ZeroOrMore(Group( tagAttrName + Suppress("=") + tagAttrValue ))) + \
Optional("/",default=[False]).setResultsName("empty").setParseAction(lambda s,l,t:t[0]=='/') + Suppress(">")
else:
printablesLessRAbrack = "".join( [ c for c in printables if c not in ">" ] )
tagAttrValue = quotedString.copy().setParseAction( removeQuotes ) | Word(printablesLessRAbrack)
openTag = Suppress("<") + tagStr + \
Dict(ZeroOrMore(Group( tagAttrName.setParseAction(downcaseTokens) + \
Optional( Suppress("=") + tagAttrValue ) ))) + \
Optional("/",default=[False]).setResultsName("empty").setParseAction(lambda s,l,t:t[0]=='/') + Suppress(">")
closeTag = Combine(_L("</") + tagStr + ">")
openTag = openTag.setResultsName("start"+"".join(resname.replace(":"," ").title().split())).setName("<%s>" % tagStr)
closeTag = closeTag.setResultsName("end"+"".join(resname.replace(":"," ").title().split())).setName("</%s>" % tagStr)
return openTag, closeTag
def makeHTMLTags(tagStr):
"""Helper to construct opening and closing tag expressions for HTML, given a tag name"""
return _makeTags( tagStr, False )
def makeXMLTags(tagStr):
"""Helper to construct opening and closing tag expressions for XML, given a tag name"""
return _makeTags( tagStr, True )
def withAttribute(*args,**attrDict):
"""Helper to create a validating parse action to be used with start tags created
with makeXMLTags or makeHTMLTags. Use withAttribute to qualify a starting tag
with a required attribute value, to avoid false matches on common tags such as
<TD> or <DIV>.
Call withAttribute with a series of attribute names and values. Specify the list
of filter attributes names and values as:
- keyword arguments, as in (class="Customer",align="right"), or
- a list of name-value tuples, as in ( ("ns1:class", "Customer"), ("ns2:align","right") )
For attribute names with a namespace prefix, you must use the second form. Attribute
names are matched insensitive to upper/lower case.
To verify that the attribute exists, but without specifying a value, pass
withAttribute.ANY_VALUE as the value.
"""
if args:
attrs = args[:]
else:
attrs = attrDict.items()
attrs = [(k,v) for k,v in attrs]
def pa(s,l,tokens):
for attrName,attrValue in attrs:
if attrName not in tokens:
raise ParseException(s,l,"no matching attribute " + attrName)
if attrValue != withAttribute.ANY_VALUE and tokens[attrName] != attrValue:
raise ParseException(s,l,"attribute '%s' has value '%s', must be '%s'" %
(attrName, tokens[attrName], attrValue))
return pa
withAttribute.ANY_VALUE = object()
opAssoc = _Constants()
opAssoc.LEFT = object()
opAssoc.RIGHT = object()
def operatorPrecedence( baseExpr, opList ):
"""Helper method for constructing grammars of expressions made up of
operators working in a precedence hierarchy. Operators may be unary or
binary, left- or right-associative. Parse actions can also be attached
to operator expressions.
Parameters:
- baseExpr - expression representing the most basic element for the nested
- opList - list of tuples, one for each operator precedence level in the
expression grammar; each tuple is of the form
(opExpr, numTerms, rightLeftAssoc, parseAction), where:
- opExpr is the pyparsing expression for the operator;
may also be a string, which will be converted to a Literal;
if numTerms is 3, opExpr is a tuple of two expressions, for the
two operators separating the 3 terms
- numTerms is the number of terms for this operator (must
be 1, 2, or 3)
- rightLeftAssoc is the indicator whether the operator is
right or left associative, using the pyparsing-defined
constants opAssoc.RIGHT and opAssoc.LEFT.
- parseAction is the parse action to be associated with
expressions matching this operator expression (the
parse action tuple member may be omitted)
"""
ret = Forward()
lastExpr = baseExpr | ( Suppress('(') + ret + Suppress(')') )
for i,operDef in enumerate(opList):
opExpr,arity,rightLeftAssoc,pa = (operDef + (None,))[:4]
if arity == 3:
if opExpr is None or len(opExpr) != 2:
raise ValueError("if numterms=3, opExpr must be a tuple or list of two expressions")
opExpr1, opExpr2 = opExpr
thisExpr = Forward()#.setName("expr%d" % i)
if rightLeftAssoc == opAssoc.LEFT:
if arity == 1:
matchExpr = FollowedBy(lastExpr + opExpr) + Group( lastExpr + OneOrMore( opExpr ) )
elif arity == 2:
if opExpr is not None:
matchExpr = FollowedBy(lastExpr + opExpr + lastExpr) + Group( lastExpr + OneOrMore( opExpr + lastExpr ) )
else:
matchExpr = FollowedBy(lastExpr+lastExpr) + Group( lastExpr + OneOrMore(lastExpr) )
elif arity == 3:
matchExpr = FollowedBy(lastExpr + opExpr1 + lastExpr + opExpr2 + lastExpr) + \
Group( lastExpr + opExpr1 + lastExpr + opExpr2 + lastExpr )
else:
raise ValueError("operator must be unary (1), binary (2), or ternary (3)")
elif rightLeftAssoc == opAssoc.RIGHT:
if arity == 1:
# try to avoid LR with this extra test
if not isinstance(opExpr, Optional):
opExpr = Optional(opExpr)
matchExpr = FollowedBy(opExpr.expr + thisExpr) + Group( opExpr + thisExpr )
elif arity == 2:
if opExpr is not None:
matchExpr = FollowedBy(lastExpr + opExpr + thisExpr) + Group( lastExpr + OneOrMore( opExpr + thisExpr ) )
else:
matchExpr = FollowedBy(lastExpr + thisExpr) + Group( lastExpr + OneOrMore( thisExpr ) )
elif arity == 3:
matchExpr = FollowedBy(lastExpr + opExpr1 + thisExpr + opExpr2 + thisExpr) + \
Group( lastExpr + opExpr1 + thisExpr + opExpr2 + thisExpr )
else:
raise ValueError("operator must be unary (1), binary (2), or ternary (3)")
else:
raise ValueError("operator must indicate right or left associativity")
if pa:
matchExpr.setParseAction( pa )
thisExpr << ( matchExpr | lastExpr )
lastExpr = thisExpr
ret << lastExpr
return ret
dblQuotedString = Regex(r'"(?:[^"\n\r\\]|(?:"")|(?:\\x[0-9a-fA-F]+)|(?:\\.))*"').setName("string enclosed in double quotes")
sglQuotedString = Regex(r"'(?:[^'\n\r\\]|(?:'')|(?:\\x[0-9a-fA-F]+)|(?:\\.))*'").setName("string enclosed in single quotes")
quotedString = Regex(r'''(?:"(?:[^"\n\r\\]|(?:"")|(?:\\x[0-9a-fA-F]+)|(?:\\.))*")|(?:'(?:[^'\n\r\\]|(?:'')|(?:\\x[0-9a-fA-F]+)|(?:\\.))*')''').setName("quotedString using single or double quotes")
unicodeString = Combine(_L('u') + quotedString.copy())
def nestedExpr(opener="(", closer=")", content=None, ignoreExpr=quotedString):
"""Helper method for defining nested lists enclosed in opening and closing
delimiters ("(" and ")" are the default).
Parameters:
- opener - opening character for a nested list (default="("); can also be a pyparsing expression
- closer - closing character for a nested list (default=")"); can also be a pyparsing expression
- content - expression for items within the nested lists (default=None)
- ignoreExpr - expression for ignoring opening and closing delimiters (default=quotedString)
If an expression is not provided for the content argument, the nested
expression will capture all whitespace-delimited content between delimiters
as a list of separate values.
Use the ignoreExpr argument to define expressions that may contain
opening or closing characters that should not be treated as opening
or closing characters for nesting, such as quotedString or a comment
expression. Specify multiple expressions using an Or or MatchFirst.
The default is quotedString, but if no expressions are to be ignored,
then pass None for this argument.
"""
if opener == closer:
raise ValueError("opening and closing strings cannot be the same")
if content is None:
if isinstance(opener,basestring) and isinstance(closer,basestring):
if len(opener) == 1 and len(closer)==1:
if ignoreExpr is not None:
content = (Combine(OneOrMore(~ignoreExpr +
CharsNotIn(opener+closer+ParserElement.DEFAULT_WHITE_CHARS,exact=1))
).setParseAction(lambda t:t[0].strip()))
else:
content = (empty+CharsNotIn(opener+closer+ParserElement.DEFAULT_WHITE_CHARS
).setParseAction(lambda t:t[0].strip()))
else:
if ignoreExpr is not None:
content = (Combine(OneOrMore(~ignoreExpr +
~Literal(opener) + ~Literal(closer) +
CharsNotIn(ParserElement.DEFAULT_WHITE_CHARS,exact=1))
).setParseAction(lambda t:t[0].strip()))
else:
content = (Combine(OneOrMore(~Literal(opener) + ~Literal(closer) +
CharsNotIn(ParserElement.DEFAULT_WHITE_CHARS,exact=1))
).setParseAction(lambda t:t[0].strip()))
else:
raise ValueError("opening and closing arguments must be strings if no content expression is given")
ret = Forward()
if ignoreExpr is not None:
ret << Group( Suppress(opener) + ZeroOrMore( ignoreExpr | ret | content ) + Suppress(closer) )
else:
ret << Group( Suppress(opener) + ZeroOrMore( ret | content ) + Suppress(closer) )
return ret
def indentedBlock(blockStatementExpr, indentStack, indent=True):
"""Helper method for defining space-delimited indentation blocks, such as
those used to define block statements in Python source code.
Parameters:
- blockStatementExpr - expression defining syntax of statement that
is repeated within the indented block
- indentStack - list created by caller to manage indentation stack
(multiple statementWithIndentedBlock expressions within a single grammar
should share a common indentStack)
- indent - boolean indicating whether block must be indented beyond the
the current level; set to False for block of left-most statements
(default=True)
A valid block must contain at least one blockStatement.
"""
def checkPeerIndent(s,l,t):
if l >= len(s): return
curCol = col(l,s)
if curCol != indentStack[-1]:
if curCol > indentStack[-1]:
raise ParseFatalException(s,l,"illegal nesting")
raise ParseException(s,l,"not a peer entry")
def checkSubIndent(s,l,t):
curCol = col(l,s)
if curCol > indentStack[-1]:
indentStack.append( curCol )
else:
raise ParseException(s,l,"not a subentry")
def checkUnindent(s,l,t):
if l >= len(s): return
curCol = col(l,s)
if not(indentStack and curCol < indentStack[-1] and curCol <= indentStack[-2]):
raise ParseException(s,l,"not an unindent")
indentStack.pop()
NL = OneOrMore(LineEnd().setWhitespaceChars("\t ").suppress())
INDENT = Empty() + Empty().setParseAction(checkSubIndent)
PEER = Empty().setParseAction(checkPeerIndent)
UNDENT = Empty().setParseAction(checkUnindent)
if indent:
smExpr = Group( Optional(NL) +
FollowedBy(blockStatementExpr) +
INDENT + (OneOrMore( PEER + Group(blockStatementExpr) + Optional(NL) )) + UNDENT)
else:
smExpr = Group( Optional(NL) +
(OneOrMore( PEER + Group(blockStatementExpr) + Optional(NL) )) )
blockStatementExpr.ignore(_bslash + LineEnd())
return smExpr
alphas8bit = srange(r"[\0xc0-\0xd6\0xd8-\0xf6\0xf8-\0xff]")
punc8bit = srange(r"[\0xa1-\0xbf\0xd7\0xf7]")
anyOpenTag,anyCloseTag = makeHTMLTags(Word(alphas,alphanums+"_:"))
commonHTMLEntity = Combine(_L("&") + oneOf("gt lt amp nbsp quot").setResultsName("entity") +";").streamline()
_htmlEntityMap = dict(zip("gt lt amp nbsp quot".split(),'><& "'))
replaceHTMLEntity = lambda t : t.entity in _htmlEntityMap and _htmlEntityMap[t.entity] or None
# it's easy to get these comment structures wrong - they're very common, so may as well make them available
cStyleComment = Regex(r"/\*(?:[^*]*\*+)+?/").setName("C style comment")
htmlComment = Regex(r"<!--[\s\S]*?-->")
restOfLine = Regex(r".*").leaveWhitespace()
dblSlashComment = Regex(r"\/\/(\\\n|.)*").setName("// comment")
cppStyleComment = Regex(r"/(?:\*(?:[^*]*\*+)+?/|/[^\n]*(?:\n[^\n]*)*?(?:(?<!\\)|\Z))").setName("C++ style comment")
javaStyleComment = cppStyleComment
pythonStyleComment = Regex(r"#.*").setName("Python style comment")
_noncomma = "".join( [ c for c in printables if c != "," ] )
_commasepitem = Combine(OneOrMore(Word(_noncomma) +
Optional( Word(" \t") +
~Literal(",") + ~LineEnd() ) ) ).streamline().setName("commaItem")
commaSeparatedList = delimitedList( Optional( quotedString | _commasepitem, default="") ).setName("commaSeparatedList")
if __name__ == "__main__":
def test( teststring ):
try:
tokens = simpleSQL.parseString( teststring )
tokenlist = tokens.asList()
print (teststring + "->" + str(tokenlist))
print ("tokens = " + str(tokens))
print ("tokens.columns = " + str(tokens.columns))
print ("tokens.tables = " + str(tokens.tables))
print (tokens.asXML("SQL",True))
except ParseBaseException,err:
print (teststring + "->")
print (err.line)
print (" "*(err.column-1) + "^")
print (err)
print()
selectToken = CaselessLiteral( "select" )
fromToken = CaselessLiteral( "from" )
ident = Word( alphas, alphanums + "_$" )
columnName = delimitedList( ident, ".", combine=True ).setParseAction( upcaseTokens )
columnNameList = Group( delimitedList( columnName ) )#.setName("columns")
tableName = delimitedList( ident, ".", combine=True ).setParseAction( upcaseTokens )
tableNameList = Group( delimitedList( tableName ) )#.setName("tables")
simpleSQL = ( selectToken + \
( '*' | columnNameList ).setResultsName( "columns" ) + \
fromToken + \
tableNameList.setResultsName( "tables" ) )
test( "SELECT * from XYZZY, ABC" )
test( "select * from SYS.XYZZY" )
test( "Select A from Sys.dual" )
test( "Select AA,BB,CC from Sys.dual" )
test( "Select A, B, C from Sys.dual" )
test( "Select A, B, C from Sys.dual" )
test( "Xelect A, B, C from Sys.dual" )
test( "Select A, B, C frox Sys.dual" )
test( "Select" )
test( "Select ^^^ frox Sys.dual" )
test( "Select A, B, C from Sys.dual, Table2 " )