[Python-Dev] slots and default values (original) (raw)

Delaney, Timothy C (Timothy) tdelaney@avaya.com
Wed, 14 May 2003 07:32:49 +1000

From: Raymond Hettinger [mailto:raymond.hettinger@verizon.net] =20 class Pane(object): slots =3D ('background', 'foreground', 'size', 'content') background =3D 'black' foreground =3D 'white' size =3D (80, 25) =20 p =3D Pane() p.background =3D 'light blue' # override the default assert p.foreground =3D=3D 'white' # other defaults still in-place

Wow - I hadn't realised that.

I would prefer to think of this is a useful feature rather than a wart. = Finally we can have true constants!

class Pane (module): # Or whatever - you get the idea ;)

__slots__ =3D ('background', 'foreground', 'size', 'content', =

'name', 'file') name =3D globals()['name'] file =3D globals()['file']

background =3D 'black'
foreground =3D 'white'
size =3D (80, 25)

import sys sys.modules[name] =3D Pane()

OK - so you could get around it by getting the class of the "module" and = then modifying that ... but it's the best yet. It even tells you that = the attribute is read-only!

Tim Delaney