What are async context managers?

Question

Accepted Answer

**Async context managers** use `async with` for resource management in async code.

```python
import asyncio

class AsyncDB:
    async def __aenter__(self):
        print("Connecting...")
        await asyncio.sleep(1)  # Simulate async connection
        return self

async def __aexit__(self, exc_type, exc_val, exc_tb):
        print("Disconnecting...")
        await asyncio.sleep(0.5)
        return False

async def query(self, sql):
        await asyncio.sleep(0.1)
        return f"Result: {sql}"

async def main():
    async with AsyncDB() as db:
        result = await db.query("SELECT * FROM users")
        print(result)

asyncio.run(main())
```

**Using contextlib:**
```python
from contextlib import asynccontextmanager

@asynccontextmanager
async def managed_resource():
    resource = await acquire()
    try:
        yield resource
    finally:
        await release(resource)
```

Python: What are async context managers?