python class and dir() function

Question

I created an empty class in python and i put that class name to dir() (dir(A)) function then it returned output like this:

['__class__', '__delattr__', '__dict__', '__doc__', '__eq__',
 '__format__', '__ge__', '__getattribute__', '__gt__', '__hash__',
 '__init__', '__le__', '__lt__', '__module__', '__ne__', '__new__',
 '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', 
 '__sizeof__', '__str__', '__subclasshook__', '__weakref__']

So I want to know from where those things came from??

Answer 1

Most of them comes from object, which all classes inherit from. But some are set when defining the new class.

set(dir(A)) - set(dir(object))

{'__dict__', '__module__', '__weakref__'}

So these three does not come from object.