为什么我在pycharm中运行graphviz.Source不显示流程图，而是显示的文字描述？

Question

为什么不显示流程图？

import sklearn
from sklearn import tree
from sklearn.datasets import load_wine
from sklearn.model_selection import train_test_split
wine = load_wine()
print(wine.data.shape)
import pandas as pd
pd.concat([pd.DataFrame(wine.data),pd.DataFrame(wine.target)],axis =1)
print(wine.feature_names)
print(wine.target_names)
#训练集测试集
xtrain,xtest,ytrain,ytest = train_test_split(wine.data,wine.target,test_size=0.3)#随机划分数据集
#注意顺序，xx,yy
print(xtrain.shape)
print(xtest.shape)
print(ytrain.shape)
print(ytest.shape)
#实例化,建模完成，总共三行代码
clf =tree.DecisionTreeClassifier(criterion = "entropy",
                                 random_state=30
                                 )#random_state=30，保证结果一样，其decisiontreeclassifier本身就具有随机性
clf = clf.fit(xtrain,ytrain)
score =clf.score(xtest,ytest)#返回预测的准确度
print(score)
import graphviz
dot_data = tree.export_graphviz(clf , feature_names=['alcohol', 'malic_acid', 'ash', 'alcalinity_of_ash', 'magnesium', 'total_phenols', 'flavanoids', 'nonflavanoid_phenols', 'proanthocyanins', 'color_intensity', 'hue', 'od280/od315_of_diluted_wines', 'proline']
                                ,class_names=['1', '2' ,'3']
                                ,filled= True
                                ,rounded= True)
graph =graphviz.Source(dot_data)
print(graph)
print(clf.feature_importances_)
feature_names=['alcohol', 'malic_acid', 'ash', 'alcalinity_of_ash', 'magnesium', 'total_phenols', 'flavanoids', 'nonflavanoid_phenols', 'proanthocyanins', 'color_intensity', 'hue', 'od280/od315_of_diluted_wines', 'proline']

print([*zip(feature_names,clf.feature_importances_)])

运行结果是一堆描述像这样

按理应该这样啊

Answer 1

graphviz 是需要独立安装，不能简单的pip install ，如果大家安装了anaconda的话，需要 conda install graphviz