globlist.py

import os
from glob import glob


def file_dir_glob_list(inlist=None):
    """Given a list of files, directories or globs, returns a fully expanded
       list of files
    """
    file_list = []    
    if inlist:
        for item in inlist:
            if os.path.isdir(item):
                # If item is a directory, get all the files in the directory
                file_list.append(glob(os.path.join('%s' % (item), '*')))
            elif item:
                # If its not a directory, then its either a glob or a file,
                # globbing it will work for either
                file_list.append(glob(item))
    else:
        file_list = file_list.append(glob('*'))

    return file_list

files = []
if isinstance(inlist, list):
    if inlist:
       for item in inlist:
            files += arg_parser(item)
    else:
        files = glob('*')
elif isinstance(inlist, str):
    names = inlist.split(',')
    for name in names:
        files = files + arg_parser(name.strip())
elif inlist is None:
    files = glob('*')

image_set = ImageSet(files)

...

def cli():
    """Give pystamps ability to run from command line"""
    parser = argparse.ArgumentParser()
    parser.add_argument(
        'file', nargs='*',
        help="Input filename or glob for files with certain extensions"
        )
    args = parser.parse_args()
    pystamps(args.file)```