How to show Matplotlib in Flask?

To show a plot in Flask, we can take the following steps−

• Make a small application.
• To run Flask application, go to the current directory.
• $ export FLASK_APP=file.py
• $ flask run
• Open the browser, hit url:http://127.0.0.1:5000/print-plot/
• To plot the figure, we can create data points for x and y using random.
• Plot data points, x and y, on the created axis.
• Write a figure into png figure format.
• Retrieve the entire contents of the BytesIO object.

Example

import io from flask import Response from matplotlib.backends.backend_agg import FigureCanvasAgg as FigureCanvas from matplotlib.figure import Figure from flask import Flask import numpy as np plt.rcParams["figure.figsize"] = [7.50, 3.50] plt.rcParams["figure.autolayout"] = True app = Flask(__name__) @app.route('/print-plot') def plot_png():    fig = Figure()    axis = fig.add_subplot(1, 1, 1)    xs = np.random.rand(100)    ys = np.random.rand(100)    axis.plot(xs, ys)    output = io.BytesIO()    FigureCanvas(fig).print_png(output)    return Response(output.getvalue(), mimetype='image/png')

Output