Chapter 15.3, Problem 15.12CP

Explanation of Solution

Event handler:

An event handler is a module is implemented in python program executes automatically when a particular event has occurred.

• If user need a program to execute an operation at that time a particular event occurs, user must create an event handler that reply at that time of event takes place.
• Event can be pressing the key or mouse operation by the user. To deal this type of operation is considered as event handlers.
  • If the defined event occurs, then call the handler function with help of object of event...