Simple, very classic Python RegExp API for modern Python

regexp.py

r"""Older, simpler interface for simple RegEx operations.

Simple regular expression interface compatible with historic regexp 
module (based on the regexp.py from Python 1.1, which was included 
without modification in subseqent versions before eventual
deletion).

Ported by Thomas Hori to use the "re" API rather than the previous
"regex" module from Python 1.x as its backend.

Due to changes in engine, while this still supports \b \B \w \W 
as in Python 0.9.5 onwards, backslashed `'<> probably do not 
carry special meaning (it does, however, support \A and \Z).

"""

import re

class Prog:
    def __init__(self, pat):
        self.prog = re.compile(pat, re.M)
    def match(self, str, offset = 0):
        s = self.prog.search(str, offset)
        if not s:
            return []
        regs = []
        for i in range(len(s.groups())+1):
            regs.append(s.span(i))
        i = len(regs)
        while i > 0 and regs[i-1] == (-1, -1):
            i = i-1
        return regs[:i]

cache_pat = None
cache_prog = None

def match(pat, str):
    global cache_pat, cache_prog
    if pat != cache_pat:
        cache_pat, cache_prog = pat, compile(pat)
    return cache_prog.match(str)

setattr(Prog,"exec",Prog.match)
error = re.error
compile = Prog
globals()["exec"] = match

__copying__ = """
Based on a file from Python 1.1, which is licensed as below.
Modifications by Thomas Hori may be used etc under the same conditions.

Copyright 1991, 1992, 1993, 1994 by Stichting Mathematisch Centrum,
Amsterdam, The Netherlands.

                        All Rights Reserved

Permission to use, copy, modify, and distribute this software and its 
documentation for any purpose and without fee is hereby granted, 
provided that the above copyright notice appear in all copies and that
both that copyright notice and this permission notice appear in 
supporting documentation, and that the names of Stichting Mathematisch
Centrum or CWI not be used in advertising or publicity pertaining to
distribution of the software without specific, written prior permission.

STICHTING MATHEMATISCH CENTRUM DISCLAIMS ALL WARRANTIES WITH REGARD TO
THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH CENTRUM BE LIABLE
FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
"""