Weird stuff about python

weird.py

a = 10
b = 10
print(a is b)

a = 10000000
b = 10000000
print(a is b)


def func(a):
    return a + 4

print(func.__closure__)

def create_closure(add):
    closed = add*add
    def closure(b):
        return a + closed
    return closure

c = create_closure(10)

print(c.__closure__)


import numbers, collections

# Virtual Base Classes
isinstance(4, numbers.Integral)  # True
numbers.Integral in int.__bases__  # False

isinstance(set(), collections.Set)  # True
collections.Set in set.__bases__  # False


# Static method descriptor
def staticmethod_(func):
    class Descriptor(object):
        def __get__(self, instance, owner):
            return func
    return Descriptor()

class S:
    @staticmethod
    def pass_through(val):
        return val

class SS:
    @staticmethod_
    def pass_through(val):
        return val

print(S().pass_through("PASSING"))
print(SS().pass_through("PASSING"))


# Class method descriptor
def classmethod_(func):
    class Descriptor(object):
        def __get__(self, instance, owner):
            def closure(*args, **kwargs):
                return func(owner, *args, **kwargs)
            return closure
    return Descriptor()

class C:
    @classmethod
    def return_class(cls):
        return cls

class CC:
    @staticmethod_
    def return_class(cls):
        return cls

class C_(C): pass
class CC_(C): pass

print(C_().return_class())
print(CC_().return_class())