Turnstyle

turnstyle.py

def generator():
    for x in range(10):
        yield x

class Turnstyle:
    def __init__(self):
        self.counter = 0

    def count(self, iterable):
        for item in iterable:
            self.counter += 1
            yield item

def main():
    l = generator()

    z = (x for x in l if x != 5)

    t = Turnstyle()

    print(t.counter)
    z = t.count(z)
    print(t.counter)

    print(list(z))
    print(t.counter)

if __name__ == '__main__':
    main()