探索Python元类与class语句协议掌握类的控制权

class MyClass:
    def __init__(self, x):
        self.x = x

    def method(self):
        return self.x

obj = MyClass(5)
print(obj.method())  # 输出：5

class MyMeta(type):
    def __new__(cls, name, bases, dct):
        dct['new_attribute'] = 5
        return super().__new__(cls, name, bases, dct)

class MySubClass(metaclass=MyMeta):
    pass

print(MySubClass.new_attribute)  # 输出：5

class MyMeta(type):
    def __new__(cls, name, bases, dct):
        print("Creating Class")
        return super().__new__(cls, name, bases, dct)

    def __init__(self, name, bases, dct):
        print("Initializing Class")
        super().__init__(name, bases, dct)

class MyClass(metaclass=MyMeta):
    pass

def my_decorator(cls):
    class NewClass(cls):
        def new_method(self):
            return "Extended Method"
    return NewClass

@my_decorator
class BaseClass:
    def original_method(self):
        return "Original Method"

obj = BaseClass()
print(obj.original_method())  # 输出："Original Method"
print(obj.new_method())  # 输出："Extended Method"

def make_class(name):
    return type(name, (object,), {'attr': 100})

NewClass = make_class('DynamicClass')
obj = NewClass()
print(obj.attr)  # 输出：100