Keras网络训练可视化调用plot_model ，ImportError: Failed to import `pydot`.

调用 keras的plot_model 函数

import keras
from keras.datasets import mnist
from keras.models import Sequential
from keras.layers import Dense, Dropout, Flatten
from keras.layers import Conv2D, MaxPooling2D
from keras import backend as K

from keras.callbacks import TensorBoard
from keras.utils import plot_model

plot_model(model,to_file=‘model.png’)

问题1：未安装pydot

ImportError: Failed to import `pydot`. Please install `pydot`. For example with `pip install pydot`.

python 中安装pydot, graphviz

C:\Users\dd>pip install pydot
Requirement already satisfied: pydot in d:\programdata\anaconda3\lib\site-packages (1.4.1)
Requirement already satisfied: pyparsing>=2.1.4 in d:\programdata\anaconda3\lib\site-packages (from pydot) (2.2.0)

C:\Users\dd>pip install graphviz
Collecting graphviz
  Downloading https://files.pythonhosted.org/packages/1f/e2/ef2581b5b86625657afd32030f90cf2717456c1d2b711ba074bf007c0f1a/graphviz-0.10.1-py2.py3-none-any.whl
Installing collected packages: graphviz
Successfully installed graphviz-0.10.1

问题2：未安装GraphViz 软件

提示错误GraphViz 软件未安装 ：

OSError: `pydot` failed to call GraphViz.Please install GraphViz (https://www.graphviz.org/) and ensure that its executables are in the $PATH.

根据提示下载 graphviz-2.38
https://graphviz.gitlab.io/download/

windows系统的话从下面地址下载：
https://graphviz.gitlab.io/_pages/Download/windows/graphviz-2.38.msi

安装好后， 设置环境变量：
Path中添加软件可执行文件所在目录。我的是
“D:\Program Files (x86)\Graphviz2.38\bin”

仍然报同样的错。
根据文章pydot 停止更新，不适用于python3.6 以上版本了。卸载，安装pydotplus。
1）首先执行如下命令：

pip uninstall pydot
pip install pydotplus

2）再打开 tensorflow ，keras ， utils 目录，修改vis_utils.py 文件，将 pydot 全部替换为pydotplus。
D:\ProgramData\Anaconda3\Lib\site-packages\tensorflow\python\keras\utils

再执行不再报错。