human
Here's a good function header given the following:
I wrote the below code

    filename = _DATA_URL.split('/')[(-1)]
    filepath = os.path.join(dataset_dir, filename)
    if (not os.path.exists(filepath)):
        def _progress(count, block_size, total_size):
            sys.stdout.write(('\r>>    Downloading    %s    %.1f%%' % (filename, ((float((count * block_size)) / float(total_size)) * 100.0))))
            sys.stdout.flush()
        (filepath, _) = urllib.request.urlretrieve(_DATA_URL, filepath, _progress)
        print()
        statinfo = os.stat(filepath)
        print('Successfully    downloaded', filename, statinfo.st_size, 'bytes.')
        tarfile.open(filepath, 'r:gz').extractall(dataset_dir)

What's a good function header?
assistant
#Here's a good function header.

def _download_and_uncompress_dataset(dataset_dir):