CustomRange (range iterator + len)

custom_range_2.7.py

class CustomRange:
    def __init__(self, max):
        self.max = max

    def __iter__(self):
        self.curr = 0
        return self

    def __len__(self):
        return self.max

    def next(self):
        numb = self.curr
        if self.curr >= self.max:
            raise StopIteration
        self.curr += 1
        return numb

if __name__ == '__main__':
    index = CustomRange(10)

    print(len(index))
    for i in index:
        print(i)

custom_range_3.5.py

class CustomRange:
    def __init__(self, max):
        self.max = max

    def __iter__(self):
        self.curr = 0
        return self

    def __len__(self):
        return self.max

    def __next__(self):
        numb = self.curr
        if self.curr >= self.max:
            raise StopIteration
        self.curr += 1
        return numb

if __name__ == '__main__':
    index = CustomRange(10)

    print(len(index))
    for i in index:
        print(i)

More info on generators for anyone interested: http://intermediatepythonista.com/python-generators