How to close window on a button click in Python Tkinter GUI

Here we will learn how to assign an action to button. 

To assign action, command option needs to be used. A value (method / function) assigned to command will be triggered on button click.

below is the code to destroy the main window on click, GUI will look like as above image

 command = action to perform

to destroy current window,  window_name.destroy  needs to assign to command option.

 #project to destroy window

 try:
     from Tkinter import *
 except:
     from tkinter import *

 mw = Tk()
 mw.geometry("500x100+50+50")
 mw.title("AETies : Automation Expert Technologies")

 label = Label(mw, text='Please click on button to close window')
 label.pack(side=LEFT)
 btn = Button(mw, text='click here', command=mw.destroy)
 btn.pack(side=LEFT)

 mw.mainloop()