On Sat, Oct 17, 2015 at 03:45:19PM -0600, Eric Snow wrote: > In a recent tracker issue about OrderedDict [1] we've had some > discussion about the use of type(od) as a replacement for > od.__class__. [...] > The more general question of when we use type(obj) vs. obj.__class__ > applies to both the language and to all the stdlib as I expect > consistency there would result in fewer surprises. I realize that > there are some places where using obj.__class__ makes more sense (e.g. > for some proxy support). There are other places where using type(obj) > is the way to go (e.g. special method lookup). However, the > difference is muddled enough that usage is inconsistent in the stdlib. > For example, C-implemented types use Py_TYPE() almost exclusively. > > So, would it make sense to establish some concrete guidelines about > when to use type(obj) vs. obj.__class__? If so, what would those be? > It may also be helpful to enumerate use cases for "type(obj) is not > obj.__class__".
I for one would like to see a definitive explanation for when they are different, and when you should use one or the other. The only obvious example I've seen is the RingBuffer from the Python Cookbook: http://code.activestate.com/recipes/68429-ring-buffer/ -- Steve _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
