Problem generating index file

[bug-maker-hong]

python3 -m tfrecord.tools.tfrecord2idx ./test_tfrecord ./index_file/

/home/star/anaconda3/envs/pytorch_hjf/lib/python3.9/runpy.py:127: RuntimeWarning: 'tfrecord.tools.tfrecord2idx' found in sys.modules after import of package 'tfrecord.tools', but prior to execution of 'tfrecord.tools.tfrecord2idx'; this may result in unpredictable behaviour
warn(RuntimeWarning(msg))

problem ： * .tfindex appears under./test_tfrecord path, empty under./index_file path