Build a Basic Python Iterator

Question

How would one create an iterative function (or iterator object) in python?

Answer 1

This question is about iterable objects, not about iterators. In Python, sequences are iterable too so one way to make an iterable class is to make it behave like a sequence, i.e. give it __getitem__ and __len__ methods. I have tested this on Python 2 and 3.

class CustomRange:

    def __init__(self, low, high):
        self.low = low
        self.high = high

    def __getitem__(self, item):
        if item >= len(self):
            raise IndexError("CustomRange index out of range")
        return self.low + item

    def __len__(self):
        return self.high - self.low


cr = CustomRange(0, 10)
for i in cr:
    print(i)