Advanced Async Patterns

Async generators, context managers, and concurrency patterns.

Overview

Master advanced async patterns.

Async Generators

import asyncio

async def async_range(n):
    for i in range(n):
        await asyncio.sleep(0.1)
        yield i

async def main():
    async for value in async_range(10):
        print(value, end=" ")

asyncio.run(main())

Async Context Managers

import asyncio
from contextlib import asynccontextmanager

@asynccontextmanager
async def database_connection():
    conn = await create_connection()
    try:
        yield conn
    finally:
        await conn.close()

async def main():
    async with database_connection() as conn:
        result = await conn.execute("SELECT * FROM users")
        print(result)

Task Groups

import asyncio

async def fetch(url):
    await asyncio.sleep(1)
    return f"Data from {url}"

async def main():
    urls = ["url1", "url2", "url3"]
    
    async with asyncio.TaskGroup() as tg:
        tasks = [tg.create_task(fetch(url)) for url in urls]
    
    results = [task.result() for task in tasks]
    print(results)

asyncio.run(main())

Practice

Build an async web scraper with task groups.