What is an async context manager for HTTP sessions?

Question

Accepted Answer

Async HTTP sessions (aiohttp) use async context managers for connection pooling.

```python
import asyncio
import aiohttp

async def fetch_all(urls):
    async with aiohttp.ClientSession() as session:
        # Connection pool is managed automatically
        tasks = []
        for url in urls:
            task = asyncio.create_task(
                fetch_one(session, url)
            )
            tasks.append(task)

results = await asyncio.gather(*tasks)
        return results

async def fetch_one(session, url):
    async with session.get(url) as response:
        return await response.text()

async def main():
    urls = ["http://api.example.com/data"] * 10
    results = await fetch_all(urls)
    print(results)

asyncio.run(main())
```

**Benefits of session context manager:**
- Reuses TCP connections (connection pooling).
- Automatic cleanup.
- Shared cookies and headers.

Python: What is an async context manager for HTTP sessions?