How can I use async iteration in Python?

How can I use async iteration in Python?

You can use async iteration in Python with the async for statement to iterate over asynchronous iterators.

Can you give me an example of an async iterator?

Sure! Here's a simple example:

import asyncio

class AsyncIterator:
    def __init__(self, n):
        self.n = n
        self.current = 0

    def __aiter__(self):
        return self

    async def __anext__(self):
        if self.current < self.n:
            await asyncio.sleep(1)  # Simulate an async operation
            self.current += 1
            return self.current
        else:
            raise StopAsyncIteration

async def main():
    async for number in AsyncIterator(5):
        print(number)

asyncio.run(main())

What happens if I try to iterate over it without async?

If you try to iterate over an async iterator without using async for, you'll get a TypeError because async iterators require an asynchronous context.

Are there any built-in async iterators in Python?

Yes, Python's asyncio library provides built-in async iterators, such as asyncio.Queue and asyncio.StreamReader.