So, building the list takes more than twice as long than the entire iteration. And as for "consumes much more resources than Python 2.6+", from my tests, it looks like a 3.x range is exactly the same size as...
Python 3 uses iterators for a lot of things where python 2 used lists.The docs give a detailed explanation including the change to range.
EDIT: You can fix it like this. For g in range(len(topDeck)): newDeck.append(bottomDeck[g]) newDeck.append(topDeck[g]) #. If total cards are odd, one card will be left in bottomDeck if(len...