Matplotlib backend selection - Mini Project: Build & Apply

Matplotlib backend selection

📖 Scenario: You want to create simple plots using Matplotlib in Python. Sometimes, Matplotlib uses different backends to show or save plots depending on your environment. You will learn how to select a backend explicitly to control how plots are displayed.

🎯 Goal: Learn how to set the Matplotlib backend to 'Agg' for saving plots without displaying them, and then switch to 'TkAgg' to display plots in a window.

📋 What You'll Learn

Create a Matplotlib plot with sample data

Set the Matplotlib backend to 'Agg' to save plots without showing

Change the backend to 'TkAgg' to display plots in a window

Save the plot to a file and then display it

💡 Why This Matters

🌍 Real World

Selecting the right Matplotlib backend is important when running Python scripts on different systems, such as servers without display or local machines with GUI.

💼 Career

Data scientists and analysts often need to save plots automatically or display them interactively depending on the task and environment.

1

Create sample data and import Matplotlib

Import matplotlib.pyplot as plt and create two lists called x and y with values [1, 2, 3, 4, 5] and [10, 20, 25, 30, 40] respectively.

Matplotlib

# Import matplotlib.pyplot as plt
# Create lists x and y with values [1, 2, 3, 4, 5] and [10, 20, 25, 30, 40]
# Your code here

Need a hint?

Use import matplotlib.pyplot as plt to import. Create lists x and y with the exact values given.

2

Set Matplotlib backend to 'Agg'

Import matplotlib and set the backend to 'Agg' using matplotlib.use('Agg'). This backend allows saving plots to files without opening a window.

Matplotlib

import matplotlib.pyplot as plt
x = [1, 2, 3, 4, 5]
y = [10, 20, 25, 30, 40]
# Import matplotlib and set backend to 'Agg'
# Your code here

Need a hint?

Use import matplotlib first, then call matplotlib.use('Agg') before importing pyplot.

3

Plot data and save to file

Use plt.plot(x, y) to create a line plot. Then save the plot to a file named 'plot.png' using plt.savefig('plot.png').

Matplotlib

import matplotlib
matplotlib.use('Agg')
import matplotlib.pyplot as plt
x = [1, 2, 3, 4, 5]
y = [10, 20, 25, 30, 40]
# Plot x and y
# Save the plot to 'plot.png'
# Your code here

Need a hint?

Use plt.plot(x, y) to draw the line and plt.savefig('plot.png') to save the image.

4

Switch backend to 'TkAgg' and display the plot

Switch the backend to 'TkAgg' using plt.switch_backend('TkAgg'). Then plot x and y again, and call plt.show() to display the plot in a window.

Matplotlib

import matplotlib
matplotlib.use('Agg')
import matplotlib.pyplot as plt
x = [1, 2, 3, 4, 5]
y = [10, 20, 25, 30, 40]
plt.plot(x, y)
plt.savefig('plot.png')
# Switch backend to 'TkAgg' using plt.switch_backend
# Plot x and y
# Show the plot
# Your code here

Need a hint?

Use plt.switch_backend('TkAgg') after saving the first plot, then replot and call plt.show() to display.