Create Countdown Timer using Python-Tkinter

Prerequisites: Python GUI – tkinter
Python Tkinter is a GUI programming package or built-in library. Tkinter provides the Tk GUI toolkit with a potent object-oriented interface. Python with Tkinter is the fastest and easiest way to create GUI applications. Creating a GUI using Tkinter is an easy task.
Approach 
 

1. Importing the module – tkinter, time
2. Create the main window (container)
3. Add number of widgets to the main window:Button, Entry
4. Apply the event Trigger on the widgets.

Below is the implementation. 
 

Output: