Python - countdown.py

from time import sleep

def countdown(t):
'''
  Defines a countdown and prints always in the same position che counter
'''
	while t:
		mins, secs = divmod(t, 60)
		timer = '{:02d}:{:02d}'.format(mins, secs)
		print(timer, end="\r")
		sleep(1)
		t -= 1
	print('End of countdown.')

timeout = int(input("Enter the time in seconds: ")) 
countdown(timeout)

I wonder why, if I set tabs as 2 spaces once confirmed and saved, the editor, transforms it into tab 8!!