"""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 1996-2001:
# Mitchell S. Chapman,
# Zachary Roadhouse,
# Tim Peters,
# Just van Rossum
# Changes by Gerard Vermeulen:
# - version 0.5
# - use keyword.kwlist
# - replace string module by str methods
__version__ = "0.5"
import keyword
import string
import re
# First a little helper, since I don't like to repeat things. (Tismer speaking)
def replace(where, what, with):
return with.join(where.split(what))
# Build up a regular expression which will match anything
# interesting, including multi-line triple-quoted strings.
commentPat = r"#[^\n]*"
pat = r"q[^\\q\n]*(\\[\000-\377][^\\q\n]*)*q"
quotePat = replace(pat, "q", "'") + "|" + replace(pat, 'q', '"')
# Way to go, Tim!
pat = r"""
qqq
[^\\q]*
(
( \\[\000-\377]
| q
( \\[\000-\377]
| [^\q]
| q
( \\[\000-\377]
| [^\\q]
)
)
)
[^\\q]*
)*
qqq
"""
pat = ''.join(pat.split()) # get rid of whitespace
tripleQuotePat = 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 = r"(^|[^a-zA-Z0-9_.\"'])"
keyPat = nonKeyPat + "(" + string.join(keyword.kwlist, "|") + ")" + nonKeyPat
matchPat = commentPat + "|" + keyPat + "|" + tripleQuotePat + "|" + quotePat
matchRE = re.compile(matchPat)
idKeyPat = "[ \t]*[A-Za-z_][A-Za-z_0-9.]*" # Ident w. leading whitespace.
idRE = re.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
idSearch = idRE.search
tags = []
tags_append = tags.append
commentTag = 'comment'
stringTag = 'string'
keywordTag = 'keyword'
identifierTag = 'identifier'
start = 0
end = searchfrom
while 1:
m = search(pytext, end)
if m is None:
break # EXIT LOOP
start = m.start()
if start >= searchto:
break # EXIT LOOP
match = m.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"]:
m = idSearch(pytext, end)
if m is not None:
start = m.start()
if start == end:
match = m.group(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 tags
def 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]`
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