Python 3 range Vs Python 2 range

Question

I recently started learning python 3.
In python 2 the range() function can be used to assign list elements:

>>> A = [] >>> A = range(0,6) >>> print A [0, 1, 2, 3, 4, 5] 

But in python 3 the range() function outputs this:

>>> A = [] >>> A = range(0,6) >>> print(A) range(0, 6) 

Why is this happening?
Why did python do this change?
Is it a boon or a bane?

Answer 1

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.

The advantage is that Python 3 doesn't need to allocate the memory if you're using a large range iterator or mapping. For example

for i in range(1000000000): print(i) 

requires a lot less memory in python 3. If you do happen to want Python to expand out the list all at once you can

list_of_range = list(range(10))