Python装饰器之类的装饰器

decorator

Decorators for Class

1.类实现装饰类的装饰器（Class Decorators）

1.1装饰器不带参数

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class Decorator:
    def __init__(self, cls):
        print('D.__init__')
        self.cls = cls
    def __call__(self, *args, **kwargs):
        print('D.__call__')
        return self.cls(*args, **kwargs)
@Decorator
class A:
    def __new__(cls, *args, **kwargs):
        print('A.__new__')
        return object.__new__(cls)
    def __init__(self, *args, **kwargs):
        print('A.__init__')
        self.args = args
        self.kwargs = kwargs
A()
A('1')

1.2装饰器带参数1

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class Decorator:
    def __init__(self, *args, **kwargs):
        print('D.__init__')
        self.args = args
        self.kwargs = kwargs
    def __call__(self, cls):
        print('D.__call__')
        return cls
@Decorator(1, 2)
class A:
    def __new__(cls, *args, **kwargs):
        print('A.__new__')
        return object.__new__(cls)
    def __init__(self, *args, **kwargs):
        print('A.__init__')
        self.args = args
        self.kwargs = kwargs
A()
A('1')

1.3装饰器带参数2

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class Decorator:
    def __init__(self, *args, **kwargs):
        print('D.__init__')
        self.args = args
        self.kwargs = kwargs
    def __call__(self, cls):
        print('D.__call__')
        def wrapper(*args, **kwargs):
            print('wrapper')
            cls(*args, **kwargs)
        return wrapper
@Decorator(1, 2)
class A:
    def __new__(cls, *args, **kwargs):
        print('A.__new__')
        return object.__new__(cls)
    def __init__(self, *args, **kwargs):
        print('A.__init__')
        self.args = args
        self.kwargs = kwargs
A()
A('1')
A('2')

2.函数实现装饰类的装饰器（Function Decorators）

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def Decorator(*args, **kwargs):
    print(args, kwargs)
    def wrapper(cls):
        print('wrapper')
        return cls
    return wrapper
@Decorator()
class A:
    def __new__(cls, *args, **kwargs):
        print('A.__new__')
        return object.__new__(cls)
    def __init__(self, *args, **kwargs):
        print('A.__init__')
        self.args = args
        self.kwargs = kwargs
A()
A('2')