[Tim Peters] >> You should also note that copying a dict key or value (no matter of >> what type) consists in its entirety of copying one machine address (a >> 4- or 8-byte pointer, depending on platform).
[Lawrence D'Oliveiro] > Actually, no. It also consists of updating reference counts as well. Not in context: dict resizing is refcount-neutral, and the CPython implementation of dict resizing exploits that (quite directly in 2.5; indirectly before 2.5). It's not just that refcounts end up the same /across/ dict resizing, it's that they're not changed internally either for the duration of the resizing operation. -- http://mail.python.org/mailman/listinfo/python-list
