How To Draw A Circle In Python

In this tutorial, we will learn how to draw a circle in Python using different approaches. Python provides a variety of libraries and packages that facilitate the process of drawing shapes, including circles. We will mainly focus on using the matplotlib library, and the turtle module, which are popular choices for creating simple graphics and shapes.

First, let’s make sure you have the required libraries installed. Open your terminal or command prompt and install matplotlib by running the following command:

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pip install matplotlib

Now that you have the required library installed, let’s explore the methods to draw a circle.

Method 1: Draw a Circle using matplotlib

Step 1: Import the required library

You will need matplotlib.pyplot and matplotlib.patches.Circle for drawing a circle. Import these using the following lines of code:

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import matplotlib.pyplot as plt
from matplotlib.patches import Circle

Step 2: Determine the circle’s center and radius

Choose the coordinates of the circle’s center point and set its radius:

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center = (5, 5)
radius = 3

Step 3: Create the figure and axis

Here, we create a new figure and axis using plt.subplots() function:

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fig, ax = plt.subplots()

Step 4: Create the circle

Use the Circle class to create a circle object using the center and radius defined earlier.

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circle_obj = Circle(center, radius, fill=False)

Step 5: Add the circle to the axis

Now, we need to add the circle object to the axis:

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ax.add_patch(circle_obj)

Step 6: Set the limits and aspect ratio

We will set the limits for the x and y axes and make sure that the aspect ratio is equal so that the circle does not appear distorted:

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ax.set_xlim(0, 10)
ax.set_ylim(0, 10)
ax.set_aspect('equal')

Step 7: Display the circle

Finally, use the show() method to display the generated circle:

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plt.show()

Here is the complete code for drawing a circle using matplotlib:

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import matplotlib.pyplot as plt
from matplotlib.patches import Circle
 
center = (5, 5)
radius = 3
 
fig, ax = plt.subplots()
 
circle_obj = Circle(center, radius, fill=False)
ax.add_patch(circle_obj)
 
ax.set_xlim(0, 10)
ax.set_ylim(0, 10)
ax.set_aspect('equal')
 
plt.show()

Method 2: Draw a Circle using turtle

The turtle module is another way of drawing shapes like circles in Python. Turtle graphics is a popular method for introducing programming to kids and is built-in to Python.

Step 1: Import the turtle module

Start by importing the turtle module:

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import turtle

Step 2: Create the turtle object

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pen = turtle.Turtle()

Step 3: Draw the circle

Using the circle() method, ask the turtle to draw a circle with the specified radius:

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pen.circle(100)

Step 4: Close the turtle window

To exit the turtle graphics window, use the following code:

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turtle.done()

Here is the complete code for drawing a circle using the turtle module:

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import turtle
 
pen = turtle.Turtle()
pen.circle(100)
 
turtle.done()

Conclusion

We have learned two methods for drawing circles in Python, using the matplotlib library and the turtle module. Both methods can be used to create simple graphics and shapes. You can try customizing the appearance of the circles, such as line width, color, or transparency, by exploring the library documentation and experimenting with different parameters. Happy coding!