Source code: Lib/glob.py
The glob module finds all the pathnames matching a specified pattern according to the rules used by the Unix shell. No tilde expansion is done, but *, ?, and character ranges expressed with  will be correctly matched. This is done by using the os.listdir() and fnmatch.fnmatch() functions in concert, and not by actually invoking a subshell. Note that unlike fnmatch.fnmatch(), glob treats filenames beginning with a dot (.) as special cases. (For tilde and shell variable expansion, use os.path.expanduser() and os.path.expandvars().)
For a literal match, wrap the meta-characters in brackets. For example, '[?]' matches the character '?'.
Return a possibly-empty list of path names that match pathname, which must be a string containing a path specification. pathname can be either absolute (like /usr/src/Python-1.5/Makefile) or relative (like ../../Tools/*/*.gif), and can contain shell-style wildcards. Broken symlinks are included in the results (as in the shell).
For example, consider a directory containing only the following files: 1.gif, 2.txt, and card.gif. glob() will produce the following results. Notice how any leading components of the path are preserved.
>>> import glob >>> glob.glob('./[0-9].*') ['./1.gif', './2.txt'] >>> glob.glob('*.gif') ['1.gif', 'card.gif'] >>> glob.glob('?.gif') ['1.gif']
If the directory contains files starting with . they won’t be matched by default. For example, consider a directory containing card.gif and .card.gif:
>>> import glob >>> glob.glob('*.gif') ['card.gif'] >>> glob.glob('.c*') ['.card.gif']