TO DO

sudo apt-get update
sudo apt-get install graphviz

参考

pip install pydot

参考

pip install pydotplus

モジュールのインポート箇所

import pandas as pd
import numpy as np
from matplotlib import pyplot as plt
%matplotlib inline
from sklearn.tree import DecisionTreeClassifier as DT
from sklearn.tree import export_graphviz
import pydotplus #追加インストールが必要だった
from IPython.display import Image

エラーメッセージ

ModuleNotFoundError                       Traceback (most recent call last)
<ipython-input-3-3de7fd06ced2> in <module>()
     5 from sklearn.tree import DecisionTreeClassifier as DT
     6 from sklearn.tree import export_graphviz
----> 7 import pydotplus
     8 from IPython.display import Image
ModuleNotFoundError: No module named 'pydotplus'

pip install pydotplus

参考