Reusable Iterator

reusable_iterator.py

from itertools import count

counter = count()


def copy_iterator(iterable, lst):
    for item in lst:
        yield item
    added = len(lst)
    for item in iterable:
        lst.append(item)
        added += 1
        yield item
    # iterate over the rest
    for item in lst[added:]:
        yield item



class ReusableIterator:

    def __init__(self, iterator):
        self.iterator = iter(iterator)
        self.accumulator = []

    def __iter__(self):
        return copy_iterator(self.iterator, self.accumulator)

    @classmethod
    def from_iterator(cls, iterator):

        return cls(iterator)


iterator = range(10)
r = ReusableIterator.from_iterator(iterator)

for item in r:
    for i2 in r:
        for i3 in r:
            print(item, i2, i3)