tf 2.6.0 默认不支持hdfs等文件系统

参考：
https://stackoverflow.com/questions/68876693/how-can-i-access-to-hdfs-file-system-in-the-latest-tensorflow-2-6-0

https://github.com/tensorflow/io/issues/335

1. 安装tensorflow-io

pip3 install tensorflow-io

然后在运行的tensorflow python程序里引入依赖：

import tensorflow_io as tfio