"""Module to analyze Python source code; for syntax coloring tools.Interface:	tags = fontify(pytext, searchfrom, searchto)The 'pytext' argument is a string containing Python source code.The (optional) arguments 'searchfrom' and 'searchto' may contain a slice in pytext. The returned value is a list of tuples, formatted like this:	[('keyword', 0, 6, None), ('keyword', 11, 17, None), ('comment', 23, 53, None), etc. ]The tuple contents are always like this:	(tag, startindex, endindex, sublist)tag is one of 'keyword', 'string', 'comment' or 'identifier'sublist is not used, hence always None. """# Based on FontText.py by Mitchell S. Chapman,# which was modified by Zachary Roadhouse,# then un-Tk'd by Just van Rossum.# Many thanks for regular expression debugging & authoring are due to:#	Tim (the-incredib-ly y'rs) Peters and Cristian Tismer# So, who owns the copyright? ;-) How about this:# Copyright 1996-1997: #	Mitchell S. Chapman,#	Zachary Roadhouse,#	Tim Peters,#	Just van Rossum__version__ = "0.3.1"import string, regex# First a little helper, since I don't like to repeat things. (Tismer speaking)import stringdef replace(where, what, with):	return string.join(string.split(where, what), with)# This list of keywords is taken from ref/node13.html of the# Python 1.3 HTML documentation. ("access" is intentionally omitted.)keywordsList = [	"del", "from", "lambda", "return",	"and", "elif", "global", "not", "try",	"break", "else", "if", "or", "while",	"class", "except", "import", "pass",	"continue", "finally", "in", "print",	"def", "for", "is", "raise"]# Build up a regular expression which will match anything# interesting, including multi-line triple-quoted strings.commentPat = "#.*"pat = "q[^\q\n]*\(\\\\[\000-\377][^\q\n]*\)*q"quotePat = replace(pat, "q", "'") + "\|" + replace(pat, 'q', '"')# Way to go, Tim!pat = """	qqq	[^\\q]*	\(		\(	\\\\[\000-\377]		\|	q			\(	\\\\[\000-\377]			\|	[^\\q]			\|	q				\(	\\\\[\000-\377]				\|	[^\\q]				\)			\)		\)		[^\\q]*	\)*	qqq"""pat = string.join(string.split(pat), '')	# get rid of whitespacetripleQuotePat = replace(pat, "q", "'") + "\|" + replace(pat, 'q', '"')# Build up a regular expression which matches all and only# Python keywords. This will let us skip the uninteresting# identifier references.# nonKeyPat identifies characters which may legally precede# a keyword pattern.nonKeyPat = "\(^\|[^a-zA-Z0-9_.\"']\)"keyPat = nonKeyPat + "\("for keyword in keywordsList:	keyPat = keyPat + keyword + "\|"keyPat = keyPat[:-2] + "\)" + nonKeyPatmatchPat = keyPat + "\|" + commentPat + "\|" + tripleQuotePat + "\|" + quotePatmatchRE = regex.compile(matchPat)idKeyPat = "[ \t]*[A-Za-z_][A-Za-z_0-9.]*"	# Ident w. leading whitespace.idRE = regex.compile(idKeyPat)def fontify(pytext, searchfrom = 0, searchto = None):	if searchto is None:		searchto = len(pytext)	# Cache a few attributes for quicker reference.	search = matchRE.search	group = matchRE.group	idSearch = idRE.search	idGroup = idRE.group		tags = []	tags_append = tags.append	commentTag = 'comment'	stringTag = 'string'	keywordTag = 'keyword'	identifierTag = 'identifier'		start = 0	end = searchfrom	while 1:		start = search(pytext, end)		if start < 0 or start >= searchto:			break	# EXIT LOOP		match = group(0)		end = start + len(match)		c = match[0]		if c not in "#'\"":			# Must have matched a keyword.			if start <> searchfrom:				# there's still a redundant char before and after it, strip!				match = match[1:-1]				start = start + 1			else:				# this is the first keyword in the text.				# Only a space at the end.				match = match[:-1]			end = end - 1			tags_append((keywordTag, start, end, None))			# If this was a defining keyword, look ahead to the			# following identifier.			if match in ["def", "class"]:				start = idSearch(pytext, end)				if start == end:					match = idGroup(0)					end = start + len(match)					tags_append((identifierTag, start, end, None))		elif c == "#":			tags_append((commentTag, start, end, None))		else:			tags_append((stringTag, start, end, None))	return tagsdef test(path):	f = open(path)	text = f.read()	f.close()	tags = fontify(text)	for tag, start, end, sublist in tags:		print tag, `text[start:end]`