__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__ = "1.3.4alpha1"
__versionTime__ = "14 December 2005 05:48"
__author__ = "Paul McGuire <ptmcg@users.sourceforge.net>"
import string
import copy,sys
import warnings
import re
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 | ... >.
"""
try:
return str(obj)
except UnicodeEncodeError, e:
return unicode(obj)
def _str2dict(strg):
return dict( [(c,0) for c in strg] )
alphas = string.lowercase + string.uppercase
nums = string.digits
hexnums = nums + "ABCDEFabcdef"
alphanums = alphas + nums
00105 class ParseBaseException(Exception):
"""base exception class for all parsing runtime exceptions"""
__slots__ = ( "loc","msg","pstr","parserElement" )
def __init__( self, pstr, loc, msg, elem=None ):
self.loc = loc
self.msg = msg
self.pstr = pstr
self.parserElement = elem
00116 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)
00135 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()
00145 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
00154 class ParseFatalException(ParseBaseException):
"""user-throwable exception thrown when inconsistent parse content
is found; stops all parsing immediately"""
pass
00159 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
00167 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", "__modal" )
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
def __init__( self, toklist, name=None, asList=True, modal=True ):
if self.__doinit:
self.__doinit = False
self.__name = None
self.__parent = None
self.__modal = modal
if isinstance(toklist, list):
self.__toklist = toklist[:]
else:
self.__toklist = [toklist]
self.__tokdict = dict()
if name:
if not self.__name:
self.__modal = self.__modal and modal
if isinstance(name,int):
name = _ustr(name)
self.__name = name
if toklist:
if isinstance(toklist,basestring):
toklist = [ toklist ]
if asList:
if isinstance(toklist,ParseResults):
self[name] = (toklist.copy(),-1)
else:
self[name] = (ParseResults(toklist[0]),-1)
self[name].__name = name
else:
try:
self[name] = toklist[0]
except TypeError:
self[name] = toklist
def __getitem__( self, i ):
if isinstance( i, (int,slice) ):
return self.__toklist[i]
else:
if self.__modal:
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,tuple):
self.__tokdict[k] = self.__tokdict.get(k,list()) + [v]
sub = v[0]
else:
self.__tokdict[k] = self.__tokdict.get(k,list()) + [(v,0)]
sub = v
if isinstance(sub,ParseResults):
sub.__parent = self
def __delitem__( self, i ):
del self.__toklist[i]
def __contains__( self, k ):
return self.__tokdict.has_key(k)
def __len__( self ): return len( self.__toklist )
def __iter__( self ): return iter( self.__toklist )
00243 def keys( self ):
"""Returns all named result keys."""
return self.__tokdict.keys()
00247 def items( self ):
"""Returns all named result keys and values as a list of tuples."""
return [(k,v[-1][0]) for k,v in self.__tokdict.items()]
00251 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 self.__tokdict.has_key( name ):
if self.__modal:
return self.__tokdict[name][-1][0]
else:
return ParseResults([ v[0] for v in self.__tokdict[name] ])
else:
return ""
return None
def __iadd__( self, other ):
if other.__tokdict:
offset = len(self.__toklist)
addoffset = ( lambda a: (a<0 and offset) or (a+offset) )
otherdictitems = [(k,(v[0],addoffset(v[1])) ) for (k,vlist) in other.__tokdict.items() for v in vlist]
for k,v in otherdictitems:
self[k] = v
if isinstance(v[0],ParseResults):
v[0].__parent = self
self.__toklist += other.__toklist
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
00305 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
00315 def asDict( self ):
"""Returns the named parse results as dictionary."""
return dict( self.items() )
00319 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.__modal = self.__modal
ret.__name = self.__name
return ret
00328 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 + " "
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:
resTag = None
if i in namedItems:
resTag = namedItems[i]
if not resTag:
if namedItemsOnly:
continue
else:
resTag = "ITEM"
out += [ nl, nextLevelIndent, "<", resTag, ">", _ustr(res), "</", 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
00386 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 col (loc,strg):
"""Returns current column within a string, counting newlines as line separators
The first column is number 1.
"""
return 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.
"""
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
The first line is number 1.
"""
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",expr,"at loc",loc,"(%d,%d)" % ( lineno(loc,instring), col(loc,instring) )
def _defaultSuccessDebugAction( instring, startloc, endloc, expr, toks ):
print "Matched",expr,"->",toks.asList()
def _defaultExceptionDebugAction( instring, loc, expr, exc ):
print "Exception raised:", exc
def nullDebugAction(*args):
"""'Do-nothing' debug action, to suppress debugging output during parsing."""
pass
00439 class ParserElement(object):
"""Abstract base level parser element class."""
DEFAULT_WHITE_CHARS = " \n\t\r"
00443 def setDefaultWhitespaceChars( chars ):
"""Overrides the default whitespace chars
"""
ParserElement.DEFAULT_WHITE_CHARS = chars
setDefaultWhitespaceChars = staticmethod(setDefaultWhitespaceChars)
def __init__( self, savelist=False ):
self.parseAction = None
self.strRepr = None
self.resultsName = None
self.saveAsList = savelist
self.skipWhitespace = True
self.whiteChars = ParserElement.DEFAULT_WHITE_CHARS
self.mayReturnEmpty = False
self.keepTabs = False
self.ignoreExprs = []
self.debug = False
self.streamlined = False
self.mayIndexError = True
self.errmsg = ""
self.modalResults = True
self.debugActions = ( None, None, None )
self.re = None
00468 def copy( self ):
"""Make a copy of this ParseElement. Useful for defining different parse actions
for the same parsing pattern, using copies of the original parse element."""
cpy = copy.copy( self )
cpy.whiteChars = ParserElement.DEFAULT_WHITE_CHARS
return cpy
00475 def setName( self, name ):
"""Define name for this expression, for use in debugging."""
self.name = name
self.errmsg = "Expected " + self.name
return self
00481 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 ParseElement 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
00493 def setParseAction( self, fn ):
"""Define action to perform when successfully matching parse element definition.
Parse action fn is a callable method with the arguments (s, loc, toks) where:
- s = the original string being parsed
- loc = the location of the matching substring
- toks = a list of the matched tokens, packaged as a ParseResults object
If the function fn modifies the tokens, it 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.
"""
self.parseAction = 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
def parse( self, instring, loc, doActions=True, callPreParse=True ):
debugging = ( self.debug )
if debugging:
if (self.debugActions[0] ):
self.debugActions[0]( instring, loc, self )
if callPreParse:
loc = self.preParse( instring, loc )
tokensStart = loc
try:
try:
loc,tokens = self.parseImpl( instring, loc, doActions )
except IndexError:
raise ParseException, ( instring, len(instring), self.errmsg, self )
except ParseException, err:
if (self.debugActions[2] ):
self.debugActions[2]( instring, tokensStart, self, err )
raise
else:
if callPreParse:
loc = self.preParse( instring, loc )
tokensStart = loc
if self.mayIndexError or loc >= len(instring):
try:
loc,tokens = self.parseImpl( instring, loc, doActions )
except IndexError:
raise ParseException, ( instring, len(instring), self.errmsg, self )
else:
loc,tokens = self.parseImpl( instring, loc, doActions )
tokens = self.postParse( instring, loc, tokens )
retTokens = ParseResults( tokens, self.resultsName, asList=self.saveAsList, modal=self.modalResults )
if self.parseAction and doActions:
if debugging:
try:
tokens = self.parseAction( instring, tokensStart, retTokens )
if tokens is not None:
if isinstance(tokens,tuple):
tokens = tokens[1]
retTokens = ParseResults( tokens,
self.resultsName,
asList=self.saveAsList and isinstance(tokens,(ParseResults,list)),
modal=self.modalResults )
except ParseException, err:
if (self.debugActions[2] ):
self.debugActions[2]( instring, tokensStart, self, err )
raise
else:
tokens = self.parseAction( instring, tokensStart, retTokens )
if tokens is not None:
if isinstance(tokens,tuple):
tokens = tokens[1]
retTokens = ParseResults( tokens,
self.resultsName,
asList=self.saveAsList and isinstance(tokens,(ParseResults,list)),
modal=self.modalResults )
if debugging:
if (self.debugActions[1] ):
self.debugActions[1]( instring, tokensStart, loc, self, retTokens )
return loc, retTokens
def tryParse( self, instring, loc ):
return self.parse( instring, loc, doActions=False )[0]
00609 def parseString( self, instring ):
"""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 not self.streamlined:
self.streamline()
self.saveAsList = True
for e in self.ignoreExprs:
e.streamline()
if self.keepTabs:
loc, tokens = self.parse( instring, 0 )
else:
loc, tokens = self.parse( instring.expandtabs(), 0 )
return tokens
00625 def scanString( self, instring ):
"""Scan the input string for expression matches. Each match will return the matching tokens, start location, and end location."""
if not self.streamlined:
self.streamline()
for e in self.ignoreExprs:
e.streamline()
if not self.keepTabs:
instring = instring.expandtabs()
instrlen = len(instring)
loc = 0
preparseFn = self.preParse
parseFn = self.parse
while loc < instrlen:
try:
loc = preparseFn( instring, loc )
nextLoc,tokens = parseFn( instring, loc, callPreParse=False )
except ParseException:
loc += 1
else:
yield tokens, loc, nextLoc
loc = nextLoc
00648 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
self.keepTabs = True
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(out)
00673 def __add__(self, other ):
"""Implementation of + operator - returns And"""
if isinstance( other, basestring ):
other = Literal( other )
return And( [ self, other ] )
00679 def __radd__(self, other ):
"""Implementation of += operator"""
if isinstance( other, basestring ):
other = Literal( other )
return other + self
00685 def __or__(self, other ):
"""Implementation of | operator - returns MatchFirst"""
if isinstance( other, basestring ):
other = Literal( other )
return MatchFirst( [ self, other ] )
00691 def __ror__(self, other ):
"""Implementation of |= operator"""
if isinstance( other, basestring ):
other = Literal( other )
return other | self
00697 def __xor__(self, other ):
"""Implementation of ^ operator - returns Or"""
if isinstance( other, basestring ):
other = Literal( other )
return Or( [ self, other ] )
00703 def __rxor__(self, other ):
"""Implementation of ^= operator"""
if isinstance( other, basestring ):
other = Literal( other )
return other ^ self
00709 def __and__(self, other ):
"""Implementation of & operator - returns Each"""
if isinstance( other, basestring ):
other = Literal( other )
return Each( [ self, other ] )
00715 def __rand__(self, other ):
"""Implementation of right-& operator"""
if isinstance( other, basestring ):
other = Literal( other )
return other & self
00721 def __invert__( self ):
"""Implementation of ~ operator - returns NotAny"""
return NotAny( self )
00725 def suppress( self ):
"""Suppresses the output of this ParseElement; useful to keep punctuation from
cluttering up returned output.
"""
return Suppress( self )
00731 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
00739 def setWhitespaceChars( self, chars ):
"""Overrides the default whitespace chars
"""
self.skipWhitespace = True
self.whiteChars = chars
00745 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
00752 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
00764 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
00772 def setDebug( self, flag=True ):
"""Enable display of debugging messages while doing pattern matching."""
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
00794 def validate( self, validateTrace=[] ):
"""Check defined expressions for valid structure, check for infinite recursive definitions."""
self.checkRecursion( [] )
00798 def parseFile( self, file_or_filename ):
"""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()
return self.parseString(file_contents)
00812 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)
00818 def setName(self, name):
s = super(Token,self).setName(name)
self.errmsg = "Expected " + self.name
s.myException.msg = self.errmsg
return s
00825 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
00834 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
00851 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.name = '"%s"' % self.match
self.errmsg = "Expected " + self.name
self.mayReturnEmpty = False
self.myException.msg = self.errmsg
self.mayIndexError = False
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
exc = self.myException
exc.loc = loc
exc.pstr = instring
raise exc
00882 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) ):
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) ):
return loc+self.matchLen, self.match
exc = self.myException
exc.loc = loc
exc.pstr = instring
raise exc
00930 def copy(self):
c = super(Keyword,self).copy()
c.identChars = Keyword.DEFAULT_KEYWORD_CHARS
return c
00935 def setDefaultKeywordChars( chars ):
"""Overrides the default Keyword chars
"""
Keyword.DEFAULT_KEYWORD_CHARS = chars
setDefaultKeywordChars = staticmethod(setDefaultKeywordChars)
00942 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() )
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
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, identCars, 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
exc = self.myException
exc.loc = loc
exc.pstr = instring
raise exc
00978 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.
"""
def __init__( self, initChars, bodyChars=None, min=1, max=0, exact=0 ):
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
self.minLen = min
if max > 0:
self.maxLen = max
else:
self.maxLen = sys.maxint
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
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]*" % \
(_escapeRegexChars(self.initCharsOrig),
_escapeRegexRangeChars(self.bodyCharsOrig),)
else:
self.reString = "[%s][%s]*" % \
(_escapeRegexRangeChars(self.initCharsOrig),
_escapeRegexRangeChars(self.bodyCharsOrig),)
self.re = re.compile( self.reString )
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):
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 throwException:
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
01092 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.
"""
01096 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 Exception,e:
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
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.keys():
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
01148 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.
"""
def __init__( self, notChars, min=1, max=0, exact=0 ):
super(CharsNotIn,self).__init__()
self.skipWhitespace = False
self.notChars = notChars
self.minLen = min
if max > 0:
self.maxLen = max
else:
self.maxLen = sys.maxint
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:
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:
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
01214 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\\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.whiteChars = "".join([c for c in self.whiteChars if c not in self.matchWhite])
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 = sys.maxint
if exact > 0:
self.maxLen = exact
self.minLen = exact
def parseImpl( self, instring, loc, doActions=True ):
if not(instring[ loc ] in self.matchWhite):
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:
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
01278 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
01301 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.whiteChars = " \t"
self.errmsg = "Expected start of line"
self.myException.msg = self.errmsg
def preParse( self, instring, loc ):
loc = super(LineStart,self).preParse(instring,loc)
if instring[loc] == "\n":
loc += 1
return loc
def parseImpl( self, instring, loc, doActions=True ):
if not( loc==0 or ( loc<len(instring) and instring[loc-1] == "\n" ) ):
exc = self.myException
exc.loc = loc
exc.pstr = instring
raise exc
return loc, []
01324 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.whiteChars = " \t"
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:
exc = self.myException
exc.loc = loc
exc.pstr = instring
raise exc
else:
return loc, []
01345 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:
if loc != self.preParse( instring, 0 ):
exc = self.myException
exc.loc = loc
exc.pstr = instring
raise exc
return loc, []
01363 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):
exc = self.myException
exc.loc = loc
exc.pstr = instring
raise exc
return loc, []
01380 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:
self.exprs = [ exprs ]
def __getitem__( self, i ):
return self.exprs[i]
def append( self, other ):
self.exprs.append( other )
self.strRepr = None
return self
01399 def leaveWhitespace( self ):
"""Extends leaveWhitespace defined in base class, and also invokes leaveWhitespace on
all contained expressions."""
self.skipWhitespace = False
self.exprs = [ copy.copy(e) for e in self.exprs ]
for e in self.exprs:
e.leaveWhitespace()
return self
01408 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()
if ( len(self.exprs) == 2 ):
other = self.exprs[0]
if ( isinstance( other, self.__class__ ) and
other.parseAction is None and
other.resultsName is None and
not other.debug ):
self.exprs = other.exprs[:] + [ self.exprs[1] ]
self.strRepr = None
other = self.exprs[-1]
if ( isinstance( other, self.__class__ ) and
other.parseAction is None and
other.resultsName is None and
not other.debug ):
self.exprs = self.exprs[:-1] + other.exprs[:]
self.strRepr = None
return self
01458 def setResultsName( self, name, listAllMatches=False ):
ret = super(ParseExpression,self).setResultsName(name,listAllMatches)
return ret
01463 def validate( self, validateTrace=[] ):
tmp = validateTrace[:]+[self]
for e in self.exprs:
e.validate(tmp)
self.checkRecursion( [] )
01470 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.
"""
def __init__( self, exprs, savelist = True ):
super(And,self).__init__(exprs, savelist)
self.mayReturnEmpty = True
for e in exprs:
if not e.mayReturnEmpty:
self.mayReturnEmpty = False
break
self.skipWhitespace = exprs[0].skipWhitespace
self.whiteChars = exprs[0].whiteChars
def parseImpl( self, instring, loc, doActions=True ):
loc, resultlist = self.exprs[0].parse( instring, loc, doActions )
for e in self.exprs[1:]:
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 )
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
01515 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 exprs:
if e.mayReturnEmpty:
self.mayReturnEmpty = True
break
def parseImpl( self, instring, loc, doActions=True ):
maxExcLoc = -1
maxMatchLoc = -1
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, err:
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:
raise maxException
return maxMatchExp.parse( instring, loc, doActions )
def __ixor__(self, other ):
if isinstance( other, basestring ):
other = Literal( other )
return self.append( 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 )
01572 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)
self.mayReturnEmpty = False
for e in exprs:
if e.mayReturnEmpty:
self.mayReturnEmpty = True
break
def parseImpl( self, instring, loc, doActions=True ):
maxExcLoc = -1
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, err:
if len(instring) > maxExcLoc:
maxException = ParseException(instring,len(instring),e.errmsg,self)
maxExcLoc = len(instring)
else:
raise maxException
def __ior__(self, other ):
if isinstance( other, basestring ):
other = Literal( other )
return self.append( 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 )
01623 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 exprs:
if not e.mayReturnEmpty:
self.mayReturnEmpty = False
break
self.skipWhitespace = True
self.optionals = [ e.expr for e in exprs if isinstance(e,Optional) ]
self.multioptionals = [ e.expr for e in exprs if isinstance(e,ZeroOrMore) ]
self.multirequired = [ e.expr for e in exprs if isinstance(e,OneOrMore) ]
self.required = [ e for e in exprs if not isinstance(e,(Optional,ZeroOrMore,OneOrMore)) ]
self.required += self.multirequired
def parseImpl( self, instring, loc, doActions=True ):
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( [ str(e) for e in tmpReqd ] )
raise ParseException(instring,loc,"Missing one or more required elements (%s)" % missing )
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 )
01703 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.skipWhitespace = expr.skipWhitespace
self.whiteChars = expr.whiteChars
def parseImpl( self, instring, loc, doActions=True ):
if self.expr is not None:
return self.expr.parse( instring, loc, doActions )
else:
raise ParseException(instring,loc,"",self)
01722 def leaveWhitespace( self ):
self.skipWhitespace = False
self.expr = copy.copy(self.expr)
if self.expr is not None:
self.expr.leaveWhitespace()
return self
01729 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 )
01754 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
01771 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, []
01785 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.skipWhitespace = False
self.mayReturnEmpty = True
self.errmsg = "Found unexpected 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:
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
01822 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 )
hasIgnoreExprs = ( len(self.ignoreExprs) > 0 )
while 1:
if hasIgnoreExprs:
loc = self.skipIgnorables( instring, loc )
loc, tmptokens = self.expr.parse( instring, loc, 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
01853 def setResultsName( self, name, listAllMatches=False ):
ret = super(ZeroOrMore,self).setResultsName(name,listAllMatches)
ret.saveAsList = True
return ret
01859 class OneOrMore(ParseElementEnhance):
"""Repetition of one or more of the given expression."""
def parseImpl( self, instring, loc, doActions=True ):
loc, tokens = self.expr.parse( instring, loc, doActions )
try:
hasIgnoreExprs = ( len(self.ignoreExprs) > 0 )
while 1:
if hasIgnoreExprs:
loc = self.skipIgnorables( instring, loc )
loc, tmptokens = self.expr.parse( instring, loc, 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
01886 def setResultsName( self, name, listAllMatches=False ):
ret = super(OneOrMore,self).setResultsName(name,listAllMatches)
ret.saveAsList = True
return ret
01892 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=None ):
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 )
except (ParseException,IndexError):
if self.defaultValue is not None:
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
01923 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 consumed. 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 ):
super( SkipTo, self ).__init__( other )
if ignore is not None:
self.expr = copy.copy( self.expr )
self.expr.ignore(ignore)
self.mayReturnEmpty = True
self.mayIndexError = False
self.includeMatch = include
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
while loc < instrlen:
try:
loc = expr.skipIgnorables( instring, loc )
expr.parse( instring, loc, doActions=False, callPreParse=False )
if self.includeMatch:
skipText = instring[startLoc:loc]
loc,mat = expr.parse(instring,loc)
if mat:
return loc, [ skipText, mat ]
else:
return loc, [ skipText ]
else:
return loc, [ instring[startLoc:loc] ]
except (ParseException,IndexError):
loc += 1
exc = self.myException
exc.loc = loc
exc.pstr = instring
raise exc
01964 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.
"""
def __init__( self, other=None ):
super(Forward,self).__init__( other, savelist=False )
def __lshift__( self, other ):
self.expr = other
self.mayReturnEmpty = other.mayReturnEmpty
self.strRepr = None
return self
01978 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
01989 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
strmethod = self.__str__
self.__class__ = _ForwardNoRecurse
if self.expr is not None:
retString = _ustr(self.expr)
else:
retString = "None"
self.__class__ = Forward
return "Forward: "+retString
class _ForwardNoRecurse(Forward):
def __str__( self ):
return "..."
02013 class TokenConverter(ParseElementEnhance):
"""Abstract subclass of ParseExpression, for converting parsed results."""
def __init__( self, expr, savelist=False ):
super(TokenConverter,self).__init__( expr )
02019 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 map( string.upper, tokenlist )
02030 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 )
if adjacent:
self.leaveWhitespace()
self.adjacent = adjacent
self.skipWhitespace = True
self.joinString = joinString
02044 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
02061 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 ]
02070 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):
ikey = _ustr(tok[0]).strip()
if len(tok)==1:
tokenlist[ikey] = ("",i)
elif len(tok)==2 and not isinstance(tok[1],ParseResults):
tokenlist[ikey] = (tok[1],i)
else:
dictvalue = tok.copy()
del dictvalue[0]
if len(dictvalue)!= 1 or (isinstance(dictvalue,ParseResults) and dictvalue.keys()):
tokenlist[ikey] = (dictvalue,i)
else:
tokenlist[ikey] = (dictvalue[0],i)
if self.resultsName:
return [ tokenlist ]
else:
return tokenlist
02100 class Suppress(TokenConverter):
"""Converter for ignoring the results of a parsed expression."""
def postParse( self, instring, loc, tokenlist ):
return []
02105 def suppress( self ):
return self
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.
"""
if combine:
return Combine( expr + ZeroOrMore( delim + expr ) ).setName(_ustr(expr)+_ustr(delim)+"...")
else:
return ( expr + ZeroOrMore( Suppress( delim ) + expr ) ).setName(_ustr(expr)+_ustr(delim)+"...")
def _escapeRegexChars(s):
for c in r"\[^$.|?*+()":
s = s.replace(c,"\\"+c)
s = s.replace("\n",r"\n")
s = s.replace("\t",r"\t")
return _ustr(s)
def _escapeRegexRangeChars(s):
for c in r"\^-]":
s = s.replace(c,"\\"+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.
"""
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
symbols = strs.split()
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:
if len(symbols)==len("".join(symbols)):
return Regex( "[%s]" % "".join( [ _escapeRegexRangeChars(sym) for sym in symbols] ) )
else:
return Regex( "|".join( [ _escapeRegexChars(sym) for sym in symbols] ) )
else:
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 ) ) )
_bslash = "\\"
printables = "".join( [ c for c in string.printable if c not in string.whitespace ] )
empty = Empty().setName("empty")
_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 = "[" + 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 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 map( str.upper, t )
def downcaseTokens(s,l,t):
"""Helper parse action to convert tokens to lower case."""
return map( str.lower, t )
def _makeTags(tagStr, xml):
"""Internal helper to construct opening and closing tag expressions, given a tag name"""
tagAttrName = Word(alphanums)
if (xml):
tagAttrValue = dblQuotedString.copy().setParseAction( removeQuotes )
openTag = "<" + Keyword(tagStr) + Dict(ZeroOrMore(Group( tagAttrName + Suppress("=") + tagAttrValue ))) + Optional("/",default="").setResultsName("empty") + ">"
else:
printablesLessRAbrack = "".join( [ c for c in printables if c not in ">" ] )
tagAttrValue = quotedString.copy().setParseAction( removeQuotes ) | Word(printablesLessRAbrack)
openTag = "<" + Keyword(tagStr,caseless=True) + Dict(ZeroOrMore(Group( tagAttrName.setParseAction(downcaseTokens) + Suppress("=") + tagAttrValue ))) + Optional("/",default="").setResultsName("empty") + ">"
closeTag = "</" + Keyword(tagStr,caseless=not xml) + ">"
openTag = openTag.setResultsName("start"+tagStr.title()).setName("<%s>" % tagStr)
closeTag = closeTag.setResultsName("end"+tagStr.title()).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 )
alphas8bit = srange(r"[\0xc0-\0xd6\0xd8-\0xf6\0xf8-\0xfe]")
_escapables = "tnrfbacdeghijklmopqsuvwxyz " + _bslash + "'" + '"'
_octDigits = "01234567"
_escapedChar = ( Word( _bslash, _escapables, exact=2 ) |
Word( _bslash, _octDigits, min=2, max=4 ) )
_sglQuote = Literal("'")
_dblQuote = Literal('"')
dblQuotedString = Combine( _dblQuote + ZeroOrMore( CharsNotIn('\\"\n\r') | _escapedChar | '""' ) + _dblQuote ).streamline().setName("string enclosed in double quotes")
sglQuotedString = Combine( _sglQuote + ZeroOrMore( CharsNotIn("\\'\n\r") | _escapedChar | "''" ) + _sglQuote ).streamline().setName("string enclosed in single quotes")
quotedString = ( dblQuotedString | sglQuotedString ).setName("quotedString using single or double quotes")
cStyleComment = Combine( Literal("/*") +
ZeroOrMore( CharsNotIn("*") | ( "*" + ~Literal("/") ) ) +
Literal("*/") ).streamline().setName("cStyleComment enclosed in /* ... */")
htmlComment = Combine( Literal("<!--") + ZeroOrMore( CharsNotIn("-") |
(~Literal("-->") + Literal("-").leaveWhitespace() ) ) +
Literal("-->") ).streamline().setName("htmlComment enclosed in <!-- ... -->")
restOfLine = Optional( CharsNotIn( "\n\r" ), default="" ).setName("rest of line up to \\n").leaveWhitespace()
dblSlashComment = "//" + restOfLine
cppStyleComment = FollowedBy("/") + ( dblSlashComment | cStyleComment )
javaStyleComment = cppStyleComment
pythonStyleComment = "#" + restOfLine
_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 ):
print teststring,"->",
try:
tokens = simpleSQL.parseString( teststring )
tokenlist = tokens.asList()
print tokenlist
print "tokens = ", tokens
print "tokens.columns =", tokens.columns
print "tokens.tables =", tokens.tables
print tokens.asXML("SQL",True)
except ParseException, err:
print err.line
print " "*(err.column-1) + "^"
print err
print
selectToken = CaselessLiteral( "select" )
fromToken = CaselessLiteral( "from" )
ident = Word( alphas, alphanums + "_$" )
columnName = Upcase( delimitedList( ident, ".", combine=True ) )
columnNameList = Group( delimitedList( columnName ) )
tableName = Upcase( delimitedList( ident, ".", combine=True ) )
tableNameList = Group( delimitedList( tableName ) )
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 " )