How to Create a Pie Chart in Python

Creating a pie chart in Python is a straightforward process, thanks to the powerful data visualization libraries available. One of the most popular libraries for creating charts and graphs is Matplotlib. In this article, we will walk through the steps to create a pie chart using Matplotlib.
‌Step 1: Install Matplotlib‌

If you haven’t installed Matplotlib yet, you can do so by using pip, the Python package installer. Open your terminal or command prompt and run the following command:

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pip install matplotlib

‌Step 2: Import the Necessary Libraries‌

Once Matplotlib is installed, you need to import it into your Python script. Additionally, for numerical calculations, it’s often useful to import NumPy as well.

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import matplotlib.pyplot as plt
import numpy as np

‌Step 3: Prepare Your Data‌

Before creating the pie chart, you need to prepare your data. This involves defining the labels for each section of the pie chart and the sizes of those sections.

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labels = 'Python', 'Java', 'C++', 'JavaScript'
sizes = [215, 130, 245, 210]

‌Step 4: Create the Pie Chart‌

Now that your data is ready, you can create the pie chart using Matplotlib’s pie() function. You can also add additional parameters to customize the appearance of the chart.

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fig1, ax1 = plt.subplots()
ax1.pie(sizes, labels=labels, autopct='%1.1f%%',
        shadow=True, startangle=90)
ax1.axis('equal')  # Equal aspect ratio ensures that pie is drawn as a circle.

plt.show()

This code snippet will create a pie chart with the specified labels and sizes. The autopct parameter is used to display the percentage of each section. The startangle parameter rotates the pie chart.
‌Step 5: Customize Your Pie Chart‌

Matplotlib allows you to customize your pie chart in various ways. For example, you can change the colors of the sections, explode one or more sections to emphasize them, and add a title to the chart.

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colors = ['gold', 'yellowgreen', 'lightcoral', 'lightskyblue']
explode = (0.1, 0, 0, 0)  # only "explode" the 1st slice (i.e., 'Python')

plt.pie(sizes, explode=explode, labels=labels, colors=colors,
        autopct='%1.1f%%', shadow=True, startangle=140)

plt.axis('equal')
plt.title('Popular Programming Languages')
plt.show()

By following these steps, you can easily create and customize pie charts in Python using Matplotlib. Pie charts are a great way to visualize the composition of data and make comparisons quickly.

[tags]
Python, Matplotlib, Pie Chart, Data Visualization, Programming