Home CPSC 110

Random Circles


To install and use the graphics library, and also get experience using random numbers.


For this lab, you will write a program which will draw random circles to the screen. The circles will have random positions, radii, and colors.


  1. First you will need to download the graphics library, as described in these instructions.
  2. Use this example program that we saw last as a starting point for the lab. It draws a red circle to the middle of the screen
  3. Make sure that you can run the program as it is. If not double-check that the graphics.py library is in the same folder as your program.
  4. Next, change it so that the circle appears at a random position on the screen. Instead of being fixed at (200, 200), you should make the X and Y coordinates random numbers between 0 and 400. Use a different random number for each.
  5. Next, make it so that the radius is also chosen randomly. It should be set to a random number between 5 and 200.
  6. Finally, make the color randomly chosen as one of three options. You can choose the three colors you want from this list. To choose an option randomly, get a random number from 1 to 3. Then use if statements to set the color based on which random number was chosen.

When you run the program, it should now make the circle show up in different places, with a different size and color (from the three you picked). Sometimes most of the circle will be off the screen, which is OK.

You will have to re-run the program for it to reset.

Extra Credit

For this lab, there is a chance for extra credit. To get it, you should modify the program so that it draws a new random circle each time the mouse is clicked inside the window.


When your program is finished, email the .py file to ifinlay@umw.edu.

Copyright © 2018 Ian Finlayson | Licensed under a Creative Commons Attribution 4.0 International License.