找到目录：

~/.keras/keras.json

如果该目录下没有该文件，你可以手动创建一个。

theano：

keras.json文件默认配置

{
    "image_dim_ordering": "th","epsilon": 1e-07,"floatx": "float32","backend": "theano" }

thesorflow：

keras.json文件默认配置

{
    "image_dim_ordering": "tf","backend": "tensorflow" }

ref:

• http://blog.csdn.net/tangwenbo124/article/details/52627774
• http://keras-cn.readthedocs.io/en/latest/backend/