How to Plot a Circle in Python?
You can easily plot a circle in Matplotlib’s Pyplot library by calling plt.gca()
to “get the current axis”. Then call the axis.add_patch()
function and pass a plt.Circle()
object into it.
For example, the one-liner
plt.gca().add_patch(plt.Circle((0.5, 0.5), 0.2, color='lightblue'))
adds a lightblue circle to the plot at position x=0.5, y=0.5 with radius r=0.2.
import matplotlib.pyplot as plt # Add a lightblue circle to the plot at position x=0.5, y=0.5 with radius r=0.2 plt.gca().add_patch(plt.Circle((0.5, 0.5), 0.2, color='lightblue')) plt.show()
The output after manually rescaling the plot area to be squared instead of rectangled (in which case it would show an “ellipse” rather than a “cirlce”):

How to Plot Multiple Circles in Python?
To plot multiple circles in Python, call plt.gca()
to “get the current axis”. Then call the axis.add_patch()
function multiple times in a for loop and pass a plt.Circle()
object into it.
Here’s an example that plots 5 circles with different colors and radiuses and locations:
import matplotlib.pyplot as plt # Data for 5 circles locations = [0.1, 0.3, 0.5, 0.7, 0.9] colors = ['b', 'g', 'r', 'y', 'grey'] radius = [0.02, 0.04, 0.08, 0.16, 0.32] # Plot 5 circles for i in range(len(locations)): circle = plt.Circle((locations[i], locations[i]), radius[i], color=colors[i], alpha=0.5) plt.gca().add_patch(circle) plt.show()
Here’s an example:

Beautiful, isn’t it? The nice pastel colors came from setting the alpha channel to 0.5, i.e., they are partially opaque.
π Recommended Tutorial: The Ultimate Guide to Python Matploblib (Video Course Free)