why 'object' class doesn't have user set attributes

Question

Every class in python inherits from the class 'object.' I am wondering about the internal mechanism of the 'object' class implementation. Why cannot the 'object' class be assigned any user-attributes? I am convinced that it is related to memory-management but what if the user thinks of implementing the memory-management himself, why can't he override 'object' class in python? This is based on my interest and want to know about which might not have any programmatic application but would be nice to know the internal feature of the language itself.

Answer 1

Types defined in C can never have user-assigned attributes. If you want to replace object globally then you'll need to iterate over every single class in existence, then replace __builtin__.object to catch all future class creation. And even that isn't reliable since the old object could be bound somewhere else.

Answer 2

This has been discussed on StackOverflow, but I'm having trouble finding the discussion to link it.

The reason I wondered is because I wanted to simplify this example:

class Box(object):
    pass

box = Box()
box.a = "some value"
box.b = 42

Here I'm using box as a sort of dictionary, one where the keys can only be identifiers. I do this because it's more convenient to write box.a than box["a"].

I wanted to do this:

box = object()
box.a = "some value"  # doesn't work

The reason is that object is the root of all objects in Python. Any attributes that object has must be in any derived type. If you want to make a large list containing a large number of objects, you want them to be as small as possible so you don't run out of memory. So object itself is minimal.

EDIT: I found the link I was trying to remember:

struct objects in python