convert a conventional generator into a coroutine

coro_from_gen.py

def coro_from_gen(generator):
    """turn a normal generator into a coroutine that can recieve and return computed data"""
    def input_pipe():
        """small internal coroutine that recieves data"""
        x = ''
        while True:
            x = yield x
            yield  # to keep the generator in lock step with input
    pipe = input_pipe()
    next(pipe)  # prime the input coroutune
    gen = generator(pipe)
    n = yield  # get first item
    while True:
        pipe.send(n)
        n = yield next(gen)
        
def test_coro_from_gen():
    """trivial working example"""
    def square(nums):
        for n in nums:
            yield n*n

    coro = coro_from_gen(square)
    next(coro)
    results = [coro.send(x) for x in range(10)]
    assert results == [0, 1, 4, 9, 16, 25, 36, 49, 64, 81]

small function to convert a generator into a coroutine. A bit niche, but useful in the right situation.