I accidentally committed this in
6375bf34fff6; this changeset addresses the
last review comments on the patch.
This is a perennial question and something someone opens a ticket for probably
every other month or so, so I'm surprised we didn't already have a FAQ entry
for it.
The original patch was written by M. Votz, refined first by Ezio Melotti and
further refined by me.
After the call to :meth:`~list.append`, the content of the mutable object has
changed from ``[]`` to ``[10]``. Since both the variables refer to the same
-object, accessing either one of them accesses the modified value ``[10]``.
+object, using either name accesses the modified value ``[10]``.
If we instead assign an immutable object to ``x``::