cancel method of asyncio task

Overview:

A Task is created and scheduled for its execution through the asyncio.create_task() function.
Once scheduled, a Task can be requested for cancellation through task.cancel() method.
If successful, a CancelledError is thrown into the coroutine corresponding to the Task.

Example:

# Example Python program that makes a cancellation
# request on a scheduled task
from datetime import date, datetime
import asyncio

# Define a coroutine
async def alarm():
   try:
       print("Task entered:%s"%datetime.now())
       for i in range (1, 10):
           print("Beep...%d"%i)
           await asyncio.sleep(1)
       print(date.today())
   except asyncio.CancelledError as e:
       print("Stopping the alarm")
   finally:
       print("Alarm stopped")
       print("Task cancelled:%s"%datetime.now())

# A coroutine for creating and cancelling tasks
async def PerformTasks(cancelAfter):
   # Create and schedule a task for execution
   t1 = asyncio.create_task(alarm())
   await asyncio.sleep(cancelAfter)

# Make a cancellation request
t1.cancel()

   # Wait for the cancellation of t1 to be complete
   await t1
   print("Hello world")

# Create a new event loop and set to asyncio
loop = asyncio.new_event_loop()
asyncio.set_event_loop(loop)

# Run the coroutine containing tasks
cancelAfter = 5
asyncio.run(PerformTasks(cancelAfter))

Output:

Task entered:2022-05-06 12:05:12.124871

Beep...1

Beep...2

Beep...3

Beep...4

Beep...5

Stopping the alarm

Alarm stopped

Task cancelled:2022-05-06 12:05:17.130425

Hello world

Cancel method of asyncio task

Overview:

Example:

Output: