Go straight to the tutorial ：

1、pip install graphviz

2、 install graphviz Windows Installation package , download msi Format ：https://graphviz.gitlab.io/_pages/Download/Download_windows.html

3、pip install pydot

4、 Add the following two sentences to your program , Because I found it's not easy to add environment variables , So just add... To the program , It's easy to use .

import os
# os.environ["PATH"] += os.pathsep + 'C:/Program Files (x86)/Graphviz2.38/bin/'

And then it's done .