Using object as a class

[Steven D'Aprano]

On Mon, 26 Mar 2018 07:31:06 -0500, D'Arcy Cain wrote:

> Is this behaviour (object not quite like a class) documented anywhere?

It's exactly like a class. It's an immutable class. You are making 
assumptions about what classes must be able to do.


> Does anyone know the rationale for this if any?

object is intended as the base class for all others. As such, it is 
absolutely dead simple, with no state and very few methods other than 
those required by everything. The usual way we use object instances is as 
identity-objects: objects with (almost) no behaviour other than their 
identity:

SENTINEL = object()
# later
if obj is SENTINEL: ...

A bit like None.

The usual way to get what you want is a simple subclass of object, but 
even more convenient:

py> from types import SimpleNamespace
py> x = SimpleNamespace(x=1, y=2, z=3)
py> x
namespace(x=1, y=2, z=3)




-- 
Steve