14.5. AsyncIO Sleep

  • Coroutine asyncio.sleep(delay, result=None)

  • Delay can be int or float

  • Block for delay seconds.

  • If result is provided, it is returned to the caller when the coroutine completes

  • Delay is not guaranteed

  • It means that this is at least X number of seconds

  • This us due, that after that time of delay, there might still be an other function running

  • This does not interrupt or preempt

The asyncio.sleep() function is a utility function that is used to pause a coroutine for a specified amount of time.

The asyncio.sleep() function is similar to the time.sleep() function in Python's standard library, but it is designed for use with asynchronous code. When a coroutine calls asyncio.sleep(), it yields control to the event loop, allowing other coroutines to run while it is paused.

Here is an example of how to use asyncio.sleep():

>>> import asyncio
>>> async def my_coroutine():
...     print("Coroutine started.")
...     await asyncio.sleep(0.5)
...     print("Coroutine resumed.")
...     await asyncio.sleep(1.0)
...     print("Coroutine complete.")
>>> asyncio.run(my_coroutine())
Coroutine started.
Coroutine resumed.
Coroutine complete.

In this example, the my_coroutine function is a coroutine that prints a message, sleeps for 0.5 second using asyncio.sleep(), prints another message, sleeps for an additional 1.0 second using asyncio.sleep(), and then prints a final message.

When the program is run, the my_coroutine function is executed using asyncio.run(). The first message is printed immediately, followed by a pause of 0.5 seconds. After the pause, the second message is printed, followed by another pause of 1.0 seconds. Finally, the third message is printed, and the coroutine is complete.

The asyncio.sleep() function is a useful tool for implementing asynchronous code in Python. It allows coroutines to pause for a specified amount of time without blocking the event loop, allowing other coroutines to run in the meantime.

14.5.1. Example

>>> import asyncio
>>> async def main():
...     result = await asyncio.sleep(0.5, 'done')
...     print(result)
>>> asyncio.run(main())