make_glob

make_glob.py

import re

def make_glob(*parts):
    """
    Reverse glob: make a 'glob_pattern_string*' from a list of strings ['glob_pattern_string_1', 'not_a_match', 'glob_pattern_string_1', 'glob_pattern_string_3']
    """
    def match_parts(partial_string):
        rx = re.compile(partial_string+'.*')
        for part in parts:
            try:
                rx.match(part).group()
                yield part
            except AttributeError:
                continue
                
    def get_match():
        avg_len = sum(map(len,parts))/len(parts)
        half_count = len(parts)/2
        for x in xrange(avg_len):
            for part in parts:
                amt = avg_len-x
                if amt > len(part):
                    continue
                part_string = part[:amt]
                if len(list(match_parts(part_string))) > half_count:
                    return part_string
                
    match = get_match()
    if not match:
        raise Exception('Cannot find glob for parts %s' % format(parts))
    return match + '*'

def test_make_glob():
    vals = ['test_strings_part-0.csv',
         'test_strings_nomatch-0',
         'no_match',
         'test_strings_part-1.csv',
         'test_strings_part-2.csv',
         'test_strings_part-3.csv',
         'test_strings_nomatch-3',
         'test_strings_part-4.csv',
         'test_strings_part-5.csv',
         'test_strings_part-6.csv',
         'test_strings_nomatch-6',
         'test_strings_part-7.csv',
         'test_strings_part-8.csv',
         'no_match',
         'test_strings_part-9.csv',
         'test_strings_nomatch-9']
    assert make_glob(*vals) == 'test_strings_part-*'
test_make_glob()