python3中的异步for循环

Question

我在这里看一个非常有趣的网站 https://faust.readthedocs.io/en/latest/我对这段代码感到惊讶：

class Order(faust.Record):
    account_id: str
    product_id: str
    price: float
    quantity: float = 1.0

orders_topic = app.topic('orders', key_type=str, value_type=Order)

@app.agent(orders_topic)
async def process_order(orders):
    async for order in orders:
        # process each order using regular Python
        total_price = order.price * order.quantity
        await send_order_received_email(order.account_id, order)

我的问题是async for order in orders是如何工作的？ 什么版本的Python引入了这种语法？你知道吗

Answer 1

它是在Python 3.5中实现的：

https://www.python.org/dev/peps/pep-0492/#asynchronous-iterators-and-async-for

Python-Version: 3.5

An asynchronous iterable is able to call asynchronous code in its iter implementation, and asynchronous iterator can call asynchronous code in its next method.