metaclass.py

def bark(self):
    print('Woof, woof')

class Animal:
    def feed(self):
        print('It is feeding time!')

Dog = type('Dog', (Animal, ), {'age':0, 'bark':bark})

print('The class name is:', Dog.__name__)
print('The class is an instance of:', Dog.__class__)
print('The class is based on:', Dog.__bases__)
print('The class attributes are:', Dog.__dict__)

doggy = Dog()
doggy.feed()
doggy.bark()



#===========================#
#own meta class
class My_Meta(type):
    def __new__(mcs, name, bases, dictionary):
        obj = super().__new__(mcs, name, bases, dictionary)
        obj.custom_attribute = 'Added by My_Meta'
        return obj

class My_Object(metaclass=My_Meta):
    pass

print(My_Object.__dict__)

#===========================#

def greetings(self):
    print('Just a greeting function, but it could be something more serious like a check sum')

class My_Meta(type):
    def __new__(mcs, name, bases, dictionary):
        if 'greetings' not in dictionary:
            dictionary['greetings'] = greetings
        obj = super().__new__(mcs, name, bases, dictionary)
        return obj

class My_Class1(metaclass=My_Meta):
    pass

class My_Class2(metaclass=My_Meta):
    def greetings(self):
        print('We are ready to greet you!')

myobj1 = My_Class1()
myobj1.greetings()
myobj2 = My_Class2()
myobj2.greetings()
#===========================#