What are async generators and when to use them?

Question

Accepted Answer

**Async generators** combine `async def` and `yield` for asynchronous iteration.

```python
import asyncio

async def fetch_page(url, page):
    await asyncio.sleep(0.5)  # Simulate network
    return {"url": url, "page": page, "data": f"Page {page}" }

async def paginate_all(url):
    page = 1
    while True:
        data = await fetch_page(url, page)
        yield data  # Async yield
        if not data.get("has_next"):
            break
        page += 1

async def main():
    async for page in paginate_all("https://api.example.com"):
        process(page)

asyncio.run(main())
```

**Use cases:**
- Streaming API responses.
- Paginated data fetching.
- Real-time data processing.
- Database cursors.

**Key differences from regular generators:**
- Uses `async for` to consume.
- Can `await` inside the generator.
- Requires event loop.

Python: What are async generators and when to use them?