def _files_in(dirname, extension):
    file_paths = [os.path.join(dirname, f) for f in os.listdir(dirname)]
    filt = lambda path: (
        os.path.isfile(path)
        and os.path.splitext(path)[-1].lower()[1:] == extension
        )
    return filter(filt, file_paths)
Returns list of files in given directory,
dataset/ETHPy150Open omangin/multimodal/multimodal/db/models/vctk.py/_files_in