Python be like:
TypeError: 'callable_iterator' object is not callable
and also:
TypeError 'callable_iterator' object is not subscriptable

Why the fuck did you name it "callable iterator" if you can't call it, or iterate it.

It's not an array, It's an iterator, iterable doesn't mean subscriptable at all. For example a linked list is iterable but not subscriptable by default unless someone writes an honestly ugly hack around it.

Not sure about the callable part honestly.

An iterator isn't iterable; A toaster isn't toastable, bread is toastable. A washing machine happens to be washable, but washing the washing machine means something completely different from using it to wash clothes.

Subscriptable implies that you can retrieve the n-th element without modifying the object. The iterator interface supports neither n-th element since it has no concept of a start or position, nor seeking.

An iterator could represent something like a blocking stream of console input, which you obviously can't subscript.