Is this a good idea?

gistfile1.py

def filter_timezones(timezone_groups):
    import re
    exclude = [
        'Etc', 'localtime', 'posix',
        'posixrules', 'right', 'SystemV',
    ]
    tab_files_re = '.*\\.tab$'

    def is_kept(zone):
        return zone not in exclude and not re.match(tab_files_re, zone)

    return [( group[0], filter(is_kept, group[1]) ) for group in timezone_groups]

comprehensions are cool, but is this going too far?

I like this a lot better