Ignore case in glob() on Linux

You can replace each alphabetic character c with [cC], via

import glob
def insensitive_glob(pattern):
    def either(c):
        return '[%s%s]' % (c.lower(), c.upper()) if c.isalpha() else c
    return glob.glob(''.join(map(either, pattern)))

Use case-insensitive regexes instead of glob patterns. fnmatch.translate generates a regex from a glob pattern, so

re.compile(fnmatch.translate(pattern), re.IGNORECASE)

gives you a case-insensitive version of a glob pattern as a compiled RE.

Keep in mind that, if the filesystem is hosted by a Linux box on a Unix-like filesystem, users will be able to create files foo, Foo and FOO in the same directory.