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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def main():
 """Main method, entry point of the script."""

    from argparse import ArgumentParser
    description = "Download a bunch of thumbnails from Wikimedia Commons"
    parser = ArgumentParser(description=description)
    source_group = parser.add_mutually_exclusive_group()
    source_group.add_argument("-l", "--list", metavar="LIST",
                              dest="file_list",
                              type=argparse.FileType('r'),
                              help='A list of files <filename,width>')
    source_group.add_argument("-c", "--category", metavar="CATEGORY",
                              dest="category_name",
                              type=str,
                              help='A category name (without prefix)')
    parser.add_argument("files", nargs='*',
                        metavar="FILES",
                        help='A list of filenames')
    parser.add_argument("-o", "--output", metavar="FOLDER",
                        dest="output_path",
                        action=Folder,
                        default=os.getcwd(),
                        help='The directory to download the files to')
    parser.add_argument("-w", "--width",
                        dest="width",
                        type=int,
                        default=100,
                        help='The width of the thumbnail (default: 100)')
    verbosity_group = parser.add_mutually_exclusive_group()
    verbosity_group.add_argument("-v",
                                 action="count",
                                 dest="verbose",
                                 default=1,
                                 help="Verbosity level. -v for DEBUG")
    verbosity_group.add_argument("-q", "--quiet",
                                 action="store_const",
                                 dest="verbose",
                                 const=0,
                                 help="To silence the INFO messages")
    args = parser.parse_args()
    logging_map = {0: logging.WARNING,
                   1: logging.INFO,
                   2: logging.DEBUG}
    logging_level = logging_map.get(args.verbose, logging.DEBUG)
    logging.basicConfig(level=logging_level)
    logging.info("Starting")

    if args.file_list:
        download_from_file_list(args.file_list, args.output_path)
    elif args.category_name:
        download_from_category(args.category_name, args.output_path, args.width)
    elif args.files:
        download_from_files(args.files, args.output_path, args.width)
    else:
        parser.print_help()