iterator with `at_end` property

iterator.py

class MyIter:

    def __init__(self, iterable):
        self._iterator = iter(iterable)
        self.at_end = False
        self._prefetch_next()

    def __next__(self):
        if self.at_end:
            raise StopIteration
        next_one = self.next_one
        self._prefetch_next()
        return next_one

    def _prefetch_next(self):
        try:
            self.next_one = next(self._iterator)
        except StopIteration:
            del self.next_one
            self.at_end = True
        
    def __iter__(self):
        return self


if __name__ == '__main__':
    vals = MyIter(range(3))
    for x in vals:
        print(x, vals.at_end)

    # PRINTS
    #  0 False
    #  1 False
    #  2 True