pydot` failed to call GraphViz.Please install GraphViz

https://stackoverflow.com/questions/36886711/keras-runtimeerror-failed-to-import-pydot-after-installing-graphviz-and-pyd

then i just 

conda install graphviz
conda install pydotplus

start steps includes:

 https://blog.csdn.net/J_______ll/article/details/79728627

win7 添加環境變量，計算機-右鍵-屬性-高級系統設置-環境變量