Use Matplotlib Inside Flask or Django
Description:
A Python program that uses Flask to generate and display a matplotlib chart on a webpage.
Code Explanation:
● First, install Flask using the command: pip install flask
● from flask import Flask, Response: Used to create the Flask web app and return an image response.
● import matplotlib.pyplot as plt: Imports matplotlib for plotting.
● import io: Used to temporarily store the plot in memory.
● app = Flask(__name__): Initializes the Flask app.
● @app.route('/'): Defines the route to handle requests to the root URL.
● fig, ax = plt.subplots(): Creates a new figure and axes.
● ax.plot(...): Plots a simple line chart with markers.
● plt.savefig(...): Saves the chart to an in-memory file.
● Response(...): Returns the image as a PNG to be displayed in the browser.
● app.run(...): Runs the Flask server.
When you run this script, your terminal will display:
Running on http://127.0.0.1:5000
Open this URL in your browser to view the chart.
Program:
from flask import Flask, Response
import matplotlib.pyplot as plt
import io
app = Flask(__name__)
@app.route('/')
def plot():
# Create a figure
fig, ax = plt.subplots()
ax.plot([1, 2, 3, 4], [10, 20, 25, 30], marker='o')
ax.set_title('Simple Line Plot')
ax.set_xlabel('X-axis')
ax.set_ylabel('Y-axis')
# Save plot to a BytesIO object
img = io.BytesIO()
plt.savefig(img, format='png')
img.seek(0)
plt.close(fig)
return Response(img.getvalue(), mimetype='image/png')
if __name__ == '__main__':
app.run(debug=True)
Output:
