Wrap a generator in a re-usable iterator

repeatable_iterator.py

class CursorIterator(object):
    def __init__(self, sequence, start=0):
        self.sequence = sequence
        self.position = start - 1

    def __next__(self):
        self.position += 1
        return self.sequence[self.position]

class RepeatableIterable(object):
    def __init__(self, iterator):
        self.iterator = iterator
        self.cache = []

    def __iter__(self):
        return CursorIterator(self)

    def __getitem__(self, i):
        while i >= len(self.cache):
            self.cache.append(next(self.iterator))
        return self.cache[i]

def gen():
    for a in range(10):
        yield a

g = gen()
print('gen 1st time:', list(g))
print('gen 2nd time:', list(g))

g2 = RepeatableIterable(gen())
print('wrapped gen 1st time:', list(g2))
print('wrapped gen 2nd time:', list(g2))