advancedAdvanced Topics

Async Programming

Write concurrent code with async/await for I/O-bound tasks.

In this lesson

01Async Basics

01Async Basics

Use async def and await for non-blocking I/O operations.

Python

1import asyncio
2
3async def fetch_data(url: str, delay: float):
4    print(f"Fetching {url}...")
5    await asyncio.sleep(delay)  # simulates I/O
6    return f"Data from {url}"
7
8async def main():
9    # Run concurrently
10    results = await asyncio.gather(
11        fetch_data("api/users", 1.0),
12        fetch_data("api/posts", 0.5),
13        fetch_data("api/comments", 0.8),
14    )
15    for r in results:
16        print(r)
17
18asyncio.run(main())

Output

Fetching api/users...
Fetching api/posts...
Fetching api/comments...
Data from api/users
Data from api/posts
Data from api/comments

Type Hints

Testing with pytest