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Python Timer cancel() Method with Example

Python Timer.cancel() Method: In this tutorial, we will learn about the cancel() method of Timer Class in Python with its usage, syntax, and examples. By Hritika Rajput Last updated : April 23, 2023

Python Timer.cancel() Method

The Timer.cancel() method is used to stop the timer and cancel the timer object execution. The action will be stopped only when the timer is still in the waiting area.

Module

The following module is required to use cancel() method:

import threading

Class

The following class is required to use cancel() method:

from threading import Timer

Syntax

The following is the syntax of cancel() method:

cancel()

Parameter(s)

The following are the parameter(s):

• None

Return Value

The return type of this method is <class 'NoneType'>. The method does not return anything. It is used to cancel a thread during its waiting time.

Example 1: Use of Timer.cancel() Method in Python

# python program to explain the
# use of cancel() method in Timer class

import threading

def helper_function(i):
  print("Value printed=",i)

if __name__=='__main__':
    
  thread1 = threading.Timer(interval = 3, function = helper_function,args = (9,))
  print("Starting the timer object")
  print()
  
  # Starting the function after 3 seconds
  thread1.start()
  
  print("This gets printed before the helper_function as helper_function starts after 3 seconds")
  print()
  
  # This cancels the thread when 3 seconds 
  # have not passed
  thread1.cancel()
  print("Thread1 cancelled, helper_function is not executed")

Output

Starting the timer object

This gets printed before the helper_function as helper_function starts after 3 seconds

Thread1 cancelled, helper_function is not executed

Example 2: Use of Timer.cancel() Method in Python

# python program to explain the
# use of cancel() method in Timer class

import threading
import time

def helper_function(i):
  print("Value printed=",i)
  print()
  
if __name__=='__main__':
    
  thread1 = threading.Timer(interval = 3, function = helper_function,args = (19,))
  print("Starting the timer object")
  print()
  
  # Starting the function after 3 seconds
  thread1.start()
  # Sleeping this thread for 5 seconds
  time.sleep(5)
  
  # This will not cancel the thread as 3 seconds have passed
  thread1.cancel()
  print("This time thread is not cancelled as 3 seconds have passed when cancel() method is called")

Output

Starting the timer object

Value printed= 19

This time thread is not cancelled as 3 seconds have passed when cancel() method is called