iterator.py

# coding: utf-8 

class MyIterator(object):
    def __init__(self, step):
        self.step = step

    def next(self):
        if self.step == 0:
            raise StopIteration
        
        self.step -= 1
        return self.step

    def __iter__(self):
        return self

if __name__ == '__main__':

    for i in MyIterator(10):
        print i