Problem to display decision tree: InvocationException: GraphViz's executables not found in Python scikit-learn? I try to display Decision Tree in Jupyter Notebook in Python. 

This is my code:

X = data.drop(["Risk"], axis=1)
y = data["Risk"]
X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.3, random_state=0)
from sklearn.tree import DecisionTreeClassifier
klasyfikator = DecisionTreeClassifier(criterion = "gini", random_state=0, max_depth=4, min_samples_leaf=1)
klasyfikator.fit(X = X, y = y)

dot_data = StringIO()
export_graphviz(klasyfikator, out_file=dot_data,  
                filled=True, rounded=True,
                special_characters=True,feature_names = X.columns,class_names=['0','1'])
graph = pydotplus.graph_from_dot_data(dot_data.getvalue())  
graph.write_png('diabetes.png')
Image(graph.create_png())


And by using above code I have Error:

InvocationException: GraphViz's executables not found


What can I do to display decision tree ? Where is a mistake ?
You need to add the graphviz/bin folder to PATH. See the tutorial here.