[Python-3000] Types and classes (original) (raw)

Guido van Rossum guido at python.org
Thu Apr 3 00:51:44 CEST 2008

I have no idea what you are saying here (and I did s/since/sense/ :-).

On Wed, Apr 2, 2008 at 3:34 PM, Benjamin Peterson <musiccomposition at gmail.com> wrote:

On Wed, Apr 2, 2008 at 5:20 PM, Guido van Rossum <guido at python.org> wrote: > > On Wed, Apr 2, 2008 at 3:03 PM, Amaury Forgeot d'Arc <amauryfa at gmail.com> wrote: > > On Wed, Apr 2, 2008 at 11:57 PM, Paul Prescod <paul at prescod.net> wrote: > > > > But does anyone else find it odd that the types of some things are > > > classes and the classes of some things are types? > > > > > > >>> type(socket.socket()) > > > <class 'socket.socket'> > > > >>> type("abc") > > > <type 'str'> > > > >>> socket.socket().class > > > <class 'socket.socket'> > > > >>> "abc".class > > > <type 'str'> > > > > > > In a recent talk I could only explain this as a historical quirk. As I > > > understand, it is now possible to make types that behave basically > > > exactly like classes and classes that behave exactly like types. Is > > > there any important difference between them anymore? > > > > I can find one difference: > > - types are written in C > > - classes are written in Python > > > > and there is a difference in behaviour: > > most types don't have a writable dict, and you cannot add members. > > classes are more flexible. > > That's more correctly described as the difference between built-in > types/classes and user-defined types/classes. > > I think it's still just a historical quirk; maybe we should bite the > bullet and fix this in py3k. (Still, 'type' and 'class' will both be > part of the language, one as a built-in function and metaclass, the > other as a keyword.) Especially because of that I think we should change. list, dict, and set aren't metaclasses, so it would make since to fix it. > > > -- > > --Guido van Rossum (home page: http://www.python.org/~guido/) > > > > _> ________________________ > Python-3000 mailing list > Python-3000 at python.org > http://mail.python.org/mailman/listinfo/python-3000 > Unsubscribe: http://mail.python.org/mailman/options/python-3000/musiccomposition%40gmail.com > -- Cheers, Benjamin Peterson

-- --Guido van Rossum (home page: http://www.python.org/~guido/)

More information about the Python-3000 mailing list