tensorflow默认的地址打不开，用如下的下载了，复制到

D:\Python38\Lib\site-packages\tensorflow\keras\models 目录

https://s3.amazonaws.com/img-datasets/mnist.npz

https://s3.amazonaws.com/text-datasets/imdb.npz

https://s3.amazonaws.com/text-datasets/imdb_word_index.json