Python's range... in Python

range-obj.py

from math import ceil


class Range(object):

    '''
    Range(start, stop, step) returns the arithmetic progression
    of numbers, whose lenght is ceil((stop - start) / step) and
    whose form [start, start + (step * 1), ..., start + (step *
    (len(obj) - 1)]. 

    Usage:
    >>> list(Range(0, 10, 3))
    [0, 3, 6, 9]
    >>> list(reversed(Range(0, 10, 3)))
    [9, 6, 3, 0]
    '''

    def __init__(self, start, stop, step):

        self.start = start
        self.stop = stop
        self.step = step

    def __repr__(self):

        return 'Range({0}, {1}, {2})'.format(self.start, self.stop, self.step)

    def __len__(self):

        return max(0, ceil((self.stop - self.start) / self.step))

    def __reversed__(self):

        return Range(self[-1], (self[0] - self.step), -self.step)

    def __getitem__(self, index):

        if not (-len(self) <= index < len(self)):
            raise IndexError('Index out of the range')
        return (self.start + (((len(self) + index) % len(self)) * self.step))