def cycle(iterable):
    """
    Returns iterator with values
    which are in iterable object.
    cycle(['A', 'B', 'C']) -> A, B, C, A, B, C, ...
    cycle(['ABCA']) -> A, B, C, A, A, B, ...
    cycle(('C')) -> C, C, C, ...
    """
    lenght = len(iterable)
    if lenght == 0:
        return iterable
    else:
        while True:
            for item in iterable:
                yield item