class myrange:
    def __init__(self, start, stop = None, step = 1):
        if stop == None:
            self._start = 0
            self._stop = start
        else:
            self._start = start
            self._stop = stop
        self._step = step

    def __iter__(self):
        return myrange_iterator(self)

class myrange_iterator:
    def __init__(self, mr):
        self._mr = mr
        self._i = mr._start

    def __iter__(self):
        return self

    def __next__(self):
        if self._i >= self._mr._stop:
            raise StopIteration
        self._i += self._mr._step

        return self._i - self._mr._step
for i in myrange(10):
    print(i, end = ' ')
print()

for i in myrange(1, 10, 2):
    print(i, end = ' ')
print()