Python list is not the same reference

Question

This is the code:

L=[1,2]

L is L[:]

False

Why is this False?

Answer 1

L[:] (slice notation) means: Make a copy of the entire list, element by element.

So you have two lists that have identical content, but are separate entities. Since is evaluates object identity, it returns False.

L == L[:] returns True.

Answer 2

When in doubt ask for id ;)

>>> li = [1,2,4]
>>> id(li)
18686240
>>> id(li[:])
18644144
>>>