python yield

"""yield demo"""


def get_yield_num(n: int):
    for i in range(n):
        yield i


def get_range_num(n: int):
    for i in range(n):
        return i


def gen_simple_demo():
    print('first call')
    yield 1
    print('second call')
    yield 2


# 使用yield发送消息
def echo():
    while True:
        message = yield
        print("收到消息：", message)


if __name__ == '__main__':
    e = echo()
    print(type(e))
    next(e)
    e.send("你好")
    e.send("再见")



    gen = get_yield_num(5)
    print(gen)
    for num in gen:
        print(num)
    print('------------------')
    print(get_range_num(5))

    gen_simple = gen_simple_demo()
    print(next(gen_simple))
    print(next(gen_simple))