zip() function in Python 3 returns an iterator. That is the reason why when you print test1 you get - <zip object at 0x1007a06c8>  . From documentation -

Make an iterator that aggregates elements from each of the iterables.

But once you do - list(test1) - you have exhausted the iterator. So after that anytime you do list(test1) would only result in empty list.

In case of test2  , you have already created the list once, test2 is a list, and hence it will always be that list.

The zip() function in Python 3 returns an iterator. That is the reason why when you print test1 you get - <zip object at 0x1007a06c8>. From documentation -

Make an iterator that aggregates elements from each of the iterables.

But once you do - list(test1) - you have exhausted the iterator. So after that anytime you do list(test1) would only result in empty list.

In case of test2, you have already created the list once, test2 is a list, and hence it will always be that list.

zip() function in Python 3 returns an iterator. That is the reason why when you print test1 you get - <zip object at 0x1007a06c8> . From documentation -

Make an iterator that aggregates elements from each of the iterables.

But once you do - list(test1) - you have exhausted the iterator. So after that anytime you do list(test1) would only result in empty list.

In case of test2 , you have already created the list once, test2 is not a list, and hence it will always be that list.

zip() function in Python 3 returns an iterator. That is the reason why when you print test1 you get - <zip object at 0x1007a06c8> . From documentation -

Make an iterator that aggregates elements from each of the iterables.

But once you do - list(test1) - you have exhausted the iterator. So after that anytime you do list(test1) would only result in empty list.

In case of test2 , you have already created the list once, test2 is a list, and hence it will always be that list.