visualize.py

import os
from PIL import Image

path = '.'

from IPython.display import Image

from sklearn.tree import export_graphviz
from matplotlib.pyplot import imshow

def image_path(fig):
    return os.path.join(path,fig)

export_graphviz(
    tree_classifier,
    out_file=image_path("wine.dot"),
    feature_names=list(df_x.drop('quality',axis=1)),
    class_names=['C', 'D', 'E', 'B', 'F', 'A'],
    rounded=True,
    filled=True
)

!dot -Tpng wine.dot -o wine.png

Image(filename='wine.png')