keras中 keras.layers merge is not callable

旧版本中：

    from keras.layers import merge
     
    merge6 = merge([layer1,layer2], mode = 'concat', concat_axis = 3)

新版本中：

    from keras.layers.merge import concatenate
     
    merge = concatenate([layer1, layer2], axis=3)

REF

https://blog.csdn.net/moshiyaofei/article/details/87888387