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[Tkinter] Is mainloop() necessary?
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[Tkinter] Is mainloop() necessary?
#1
Henlo,
I'm a noob to Python and Tkinter, learning things, Using Python 3.7.4 in a Windows PC, using default IDLE for programming. This is a simple test program for example to my question.

-----------------------
#Example-1
from tkinter import *

def printer(event):
    print('Printing')

root = Tk()

frame1 = Frame(root)
frame1.pack()

button1 = Button(root, text='Button', command=printer)
button1.pack()

root.mainloop()
------------------------

question on Example-1:

If I keep or remove root.mainloop() results will be same, program will run indefinitely. If I keep, it will run without a >>> in the interactive shell of IDLE and on closing the window manually, >>> comes back. If I run it without .mainloop(), >>> comes immediately. On manual closing it another >>> comes on the shell. Button works all the time, until I close it manually. Not only Example-1, all programs works without .mainloop(). If I try to exit any program using a custom exit button/menu item, command line functions cease to respond but window remains open with all widgets on it. Same thing happens when I double click on .py file and let it run on windows command prompt. Is it normal? or a bug? or I'm doing something wrong?
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Messages In This Thread
Is mainloop() necessary? - by escape_freedom13 - Sep-01-2019, 01:06 PM
RE: Is mainloop() necessary? - by Yoriz - Sep-01-2019, 02:35 PM
RE: Is mainloop() necessary? - by escape_freedom13 - Sep-01-2019, 02:49 PM

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