re.compile fails for verbose re with more than one group

[gcorral]

BPO	674264
Nosy	@mwhudson

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = None
closed_at = <Date 2003-02-05.14:12:56.000>
created_at = <Date 2003-01-24.20:36:28.000>
labels = ['expert-regex', 'invalid']
title = 're.compile fails for verbose re with more than one group'
updated_at = <Date 2003-02-05.14:12:56.000>
user = 'https://bugs.python.org/gcorral'

bugs.python.org fields:

activity = <Date 2003-02-05.14:12:56.000>
actor = 'mwh'
assignee = 'effbot'
closed = True
closed_date = None
closer = None
components = ['Regular Expressions']
creation = <Date 2003-01-24.20:36:28.000>
creator = 'gcorral'
dependencies = []
files = []
hgrepos = []
issue_num = 674264
keywords = []
message_count = 3.0
messages = ['14199', '14200', '14201']
nosy_count = 4.0
nosy_names = ['mwh', 'effbot', 'glchapman', 'gcorral']
pr_nums = []
priority = 'normal'
resolution = 'not a bug'
stage = None
status = 'closed'
superseder = None
type = None
url = 'https://bugs.python.org/issue674264'
versions = ['Python 2.2']

[gcorral]

The third of the following three regular expressions
fails to compile with "unbalanced parenthesis" error:

[foo.py]

import re

_good_re =
re.compile(r'\s*(elif|else|except|finally).*:\s*(#.*)$')

_also_good_re = re.compile(r'''
    \s*
    ( elif
    | else
    | except
    | finally
    )
    .*:
''', re.VERBOSE)

_bad_re = re.compile(r'''
    \s*
    ( elif
    | else
    | except
    | finally
    )
    .*:\s*(#.*)?$
''', re.VERBOSE)

>>> import foo
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
  File "zzz.py", line 15, in ?
    _bad_re = re.compile(r'''
  File "/usr/local/lib/python2.2/sre.py", line 178, in
compile
    return _compile(pattern, flags)
  File "/usr/local/lib/python2.2/sre.py", line 228, in
_compile
    raise error, v # invalid expression
sre_constants.error: unbalanced parenthesis

[glchapman]

Logged In: YES
user_id=86307

The problem here is the '#' character in the third pattern. When using re.VERBOSE, it is taken as beginning a comment (unless preceeded by a backslash). Change that line to:

.*:\s*(\#.*)?$

and the pattern will compile.

[mwhudson]

Logged In: YES
user_id=6656

Ta.