[英]Higher-order function on async coroutine
Let's say I have a function :假设我有一个功能:
def f(x):
return {"x": x}
I can create a higher-order function that behaves like so :我可以创建一个高阶函数,其行为如下:
def augment(func):
def augmented_function(x):
return {**func(x), "metadata": "test"}
return augmented_function
And then augment(f)(1)
will return {"x": 1, "metadata": "test"}
.然后augment(f)(1)
将返回{"x": 1, "metadata": "test"}
。
But what if f
is an async coroutine, this augment function does not work ( RuntimeWarning: coroutine 'f' was never awaited
and TypeError: 'coroutine' object is not a mapping
) - I want the augmented function to be a coroutine that can be awaited :但是如果f
是一个异步协程,这个增强函数将不起作用( RuntimeWarning: coroutine 'f' was never awaited
and TypeError: 'coroutine' object is not a mapping
) - 我希望增强函数是一个协程,可以等待:
async def f(x):
return {"x": x}
def augment_async(coro):
xxx
augment_async(f)(1) # Should return <coroutine object xxx>
await augment_async(f)(1) # Should return {"x": 1, "metadata": "test"}
Does anyone know how to write augment_async
in this case?有谁知道在这种情况下如何编写augment_async
?
Thanks.谢谢。
EDIT : Bonus question.编辑:奖金问题。
How to write augment_async
such as await augment_async(f(1))
returns {"x": 1, "metadata": "test"}
?如何写augment_async
如await augment_async(f(1))
返回{"x": 1, "metadata": "test"}
?
It is sufficient to make the inner function async
, so that it can await
the wrapped function:使内部函数async
就足够了,以便它可以await
被包装的函数:
def augment_async(func):
async def augmented_function(x):
return {**await func(x), "metadata": "test"}
return augmented_function
await augment_async(f)(1) # evaluates to {"x": 1, "metadata": "test"}
To “augment” an instantiated coroutine f(1)
, a single layer is sufficient:要“增强”实例化的协程f(1)
,单层就足够了:
async def direct_async(coro):
return {**await coro, "metadata": "test"}
Note that unlike augment_async
, which produces a factory for coroutines, direct_async
produces a coroutine directly - its result may be await
ed only once.请注意,与生成协程工厂的增加augment_async
不同, direct_async
直接生成一个协程 - 它的结果可能只被await
一次。
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