为什么此Python类具有不同的地址？

Question

I made a simple class:

class Foo:
    pass

then I checked its address with id :

>>> id(Foo)
4299236488

As I was curious, I checked another way:

>>> id(Foo())
4332721208

Why do they have two different addresses?

Answer 1

Foo is an object and Foo() is an instance of the object Foo .

>>> type(Foo)
<type 'classobj'>
>>> id(Foo)
140710195094936

>>> type(Foo())
<type 'instance'>
>>> id(Foo())
140710195200224

Answer 2

You did not check it in another way.

When you call foo you just ask where your class is located.

When you called foo() you created an instance of you class. And then ask where your instance of your class is located.