YouTip

What is Async?

Asynchronous programming allows your program to handle multiple tasks concurrently without threads. Python3 provides the asyncio module.

async/await Basics

import asyncio

async def say_hello():
    print("Hello...")
    await asyncio.sleep(1)
    print("World!")

asyncio.run(say_hello())

Concurrent Tasks

import asyncio

async def fetch_data(name, delay):
    await asyncio.sleep(delay)
    return f"{name} data"

async def main():
    results = await asyncio.gather(
        fetch_data("users", 2),
        fetch_data("posts", 1),
        fetch_data("comments", 3)
    )
    print(results)

asyncio.run(main())

Summary

• async def defines a coroutine function
• await pauses execution until the coroutine completes
• asyncio.gather() runs multiple coroutines concurrently