coroutine_chaining.py

def producer(sentence: str, next_coroutine):
    """Split strings and feed it to pattern_filter coroutine."""
    tokens = sentence.split(" ")
    for token in tokens:
        next_coroutine.send(token)
    next_coroutine.close()


def pattern_filter(pattern="ing", next_coroutine=None):
    """Search for pattern and if pattern got matched, send it to print_token coroutine."""
    print(f"Search for {pattern} pattern")
    try:
        while True:
            token = yield
            if pattern in token:
                next_coroutine.send(token)
    except GeneratorExit:
        print("Done with filtering")


def print_token():
    """Act as a sink, simply print the token."""
    print("I'm sink, I'll print tokens")
    try:
        while True:
            token = yield
            print(token)
    except GeneratorExit:
        print("Done with printing")


if __name__ == "__main__":
    pt = print_token()
    next(pt)
    pf = pattern_filter(next_coroutine=pt)
    next(pf)
    sentence = "Bob is running behind a fast moving car"
    producer(sentence, pf)