if hasattr(sys.stdout, "isatty") and sys.stdout.isatty():
        def print_progress(the_size, uncomp_size):
            the_size = (the_size * 100.0 / uncomp_size) if uncomp_size != 0 else 0
            txt_msg = "Unzipping %d %%"
            if the_size > print_progress.last_size + 1: