Pie charts show how a whole is divided into parts. Use plt.pie() — pass a list of values and matplotlib calculates the proportions automatically.

A basic pie chart only needs the data values. Labels are optional but strongly recommended:

import matplotlib.pyplot as plt sizes = [35, 25, 20, 15, 5] labels = [ 'Python', 'JavaScript', 'Java', 'C++', 'Other' ] plt.pie(sizes, labels=labels) plt.title('Language Market Share') plt.show()

Python

Run Code

Output

The values don't need to sum to 100 — matplotlib calculates each slice's percentage from the total automatically.

Add the autopct parameter to display percentages directly on each slice. '%1.1f%%' shows one decimal place:

import matplotlib.pyplot as plt sizes = [35, 25, 20, 15, 5] labels = [ 'Python', 'JavaScript', 'Java', 'C++', 'Other' ] plt.pie( sizes, labels=labels, autopct='%1.1f%%' ) plt.title('Language Market Share') plt.show()

Python

Run Code

Output