async_future_cache

import asyncio

futures = {}

def async_future_cache(func):
    async def wrapped(*args, **kwargs): 
        if args in futures:
            return await futures[args]
        f = asyncio.Future()
        futures[args] = f
        result = await func(*args, **kwargs)
        f.set_result(result)
        futures.pop(args)
        return result
    
    return wrapped
    
# example

import random
@async_future_cache
async def my_func(key):
    print('running my func')
    await asyncio.sleep(0.1)
    return random.random()
    
await asyncio.gather(*[my_func(123) for i in range(10)])