Keras source code analysis

Keras-backend-common.py
mainly defines three variables here:
_FLOATX = 'float32', _EPSION = 1e-7, _IMAGE_DATA_FORMAT = 'channels_last'
Multiple methods: epsilon, set_epsilon, floatx, set_floatx, cast_to_floatx, image_data_format, set_image_data_format, Each method of set_image_dim_ordering and image_dim_ordering
is very simple. The set series is to set other types of variables as corresponding variables, and the non-set series mainly return the value of the variable.