If Python slice copy the reference, why can't I use it to modify the original list?

Question

I know that Slicing lists does not generate copies of the objects in the list; it just copies the references to them.

But if that\'s the case, then why doesn\'t this wor

Answer 1

Slicing a list returns a new shallowly-copied list object. While you are correct that it does not deep-copy the original list's items, the result is a brand new list distinct from the original.

See the Python 3 tutorial:

All slice operations return a new list containing the requested elements. This means that the following slice returns a shallow copy of the list:

>>> squares = [1, 4, 9, 16, 25]
>>> squares[:]
[1, 4, 9, 16, 25]

Consider

>>> squares[:] is squares
False