Python glob but against a list of strings rather than the filesystem

Question

I want to be able to match a pattern in glob format to a list of strings, rather than to actual files in the filesystem. Is there any way to do this, or convert a glob

Answer 1

Good artists copy; great artists steal.

I stole ;)

fnmatch.translate translates globs ? and * to regex . and .* respectively. I tweaked it not to.

import re

def glob2re(pat):
    """Translate a shell PATTERN to a regular expression.

    There is no way to quote meta-characters.
    """

    i, n = 0, len(pat)
    res = ''
    while i < n:
        c = pat[i]
        i = i+1
        if c == '*':
            #res = res + '.*'
            res = res + '[^/]*'
        elif c == '?':
            #res = res + '.'
            res = res + '[^/]'
        elif c == '[':
            j = i
            if j < n and pat[j] == '!':
                j = j+1
            if j < n and pat[j] == ']':
                j = j+1
            while j < n and pat[j] != ']':
                j = j+1
            if j >= n:
                res = res + '\\['
            else:
                stuff = pat[i:j].replace('\\','\\\\')
                i = j+1
                if stuff[0] == '!':
                    stuff = '^' + stuff[1:]
                elif stuff[0] == '^':
                    stuff = '\\' + stuff
                res = '%s[%s]' % (res, stuff)
        else:
            res = res + re.escape(c)
    return res + '\Z(?ms)'

This one à la fnmatch.filter, both re.match and re.search work.

def glob_filter(names,pat):
    return (name for name in names if re.match(glob2re(pat),name))

Glob patterns and strings found on this page pass test.

pat_dict = {
            'a/b/*/f.txt': ['a/b/c/f.txt', 'a/b/q/f.txt', 'a/b/c/d/f.txt','a/b/c/d/e/f.txt'],
            '/foo/bar/*': ['/foo/bar/baz', '/spam/eggs/baz', '/foo/bar/bar'],
            '/*/bar/b*': ['/foo/bar/baz', '/foo/bar/bar'],
            '/*/[be]*/b*': ['/foo/bar/baz', '/foo/bar/bar'],
            '/foo*/bar': ['/foolicious/spamfantastic/bar', '/foolicious/bar']

        }
for pat in pat_dict:
    print('pattern :\t{}\nstrings :\t{}'.format(pat,pat_dict[pat]))
    print('matched :\t{}\n'.format(list(glob_filter(pat_dict[pat],pat))))