Using an iterator in python?

Question

I have just learned about iterators in Python however I am having a hard time implementing them.

I am trying to write a class to so that this loop works:

Answer 1

This will give you an iterator-like object which provides even or odd numbers. However, it won't satisfy your for loop semantics as it is not a true iterator.

class NumberIterator(object):
    """Returns simple even/odd number iterators."""
    def __init__(self, current):
        self.current = current
    def next(self):
        self.current += 2
        return self.current
    @classmethod
    def getOddIterator(cls):
        return cls(-1) # start at 1
    @classmethod
    def getEvenIterator(cls):
        return cls(0) # start at 2


    odd_numbers = NumberIterator.getOddIterator()
    even_numbers = NumberIterator.getEvenIterator()

    odd_numbers.next() # Returns 1
    odd_numbers.next() # Returns 3