title: How to change Canvas background color on click using button using tkinter in python
body: <p>I wanted to create a simple program to change the background colour of canvas in python using tkinter.</p>
  
  <p>The should work like this:</p>
  
  <p>suppose the current background colour of my canvas is red, the user clicks on a button on the canvas, then colour changes to blue, the user again clicks the button on the canvas, this time the colour changes  to yellow. </p>
  
  <p>I need a simple program without classes if possible.</p>