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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():
 """Test program for verifying this files functionality."""

    global __verbose
    # Parse CMD args
    parser = argparse.ArgumentParser(description='DFU Python Util')
    #parser.add_argument("path", help="file path")
    parser.add_argument(
        "-l", "--list",
        help="list available DFU devices",
        action="store_true",
        default=False
    )
    parser.add_argument(
        "-m", "--mass-erase",
        help="mass erase device",
        action="store_true",
        default=False
    )
    parser.add_argument(
        "-u", "--upload",
        help="read file from DFU device",
        dest="path",
        default=False
    )
    parser.add_argument(
        "-v", "--verbose",
        help="increase output verbosity",
        action="store_true",
        default=False
    )
    args = parser.parse_args()

    __verbose = args.verbose

    if args.list:
        list_dfu_devices(idVendor=__VID, idProduct=__PID)
        return

    init()

    if args.mass_erase:
        print ("Mass erase...")
        mass_erase()

    if args.path:
        elements = read_dfu_file(args.path)
        if not elements:
            return
        print("Writing memory...")
        write_elements(elements, args.mass_erase, progress=cli_progress)

        print("Exiting DFU...")
        exit_dfu()
        return

    print("No command specified")