classCircle:def__init__(self,radius):self.radius=radius@classmethoddeffrom_diameter(cls,diameter):returncls(diameter/2)@propertydefdiameter(self):returnself.radius*2@diameter.setterdefdiameter(self,diameter):self.radius=diameter/2c=Circle.from_diameter(8)print(c.radius)# 4.0print(c.diameter)# 8....
defdecorator(aClass):classnewClass:def__init__(self,age):self.total_display=0self.wrapped=aClass(age)defdisplay(self):self.total_display+=1print("total display",self.total_display)self.wrapped.display()returnnewClass @decoratorclassBird:def__init__(self,age):self.age=age defdisplay(self):...
2.5 dataclass @dataclass装饰器(Python 3.7引入)可以自动为一个类生成几个特殊的方法,如__init__、__repr__、__eq__、__lt__等。 因此,它可以为我们节省大量编写这些基本方法的时间。如果一个类主要用于存储数据,那么@dataclass 装饰器是最好的选择。 为了演示,下面的示例只定义了一个名为 Point 的类的...
classMyDecorator:def__init__(self,fn):self.fn=fndef__call__(self,*args, **kwargs):print('Decoration before execution of function')self.fn(*args, **kwargs)print('Decoration after execution of function\n')deffunc(message, name):print(message, name) func= MyDecorator(func) The classMy...
classlocker:def__init__(self):print("locker.__init__() should be not called.")@staticmethoddefacquire():print("locker.acquire() called.(这是静态方法)")@staticmethoddefrelease():print(" locker.release() called.(不需要对象实例)")defdeco(cls):'''cls 必须实现acquire和release静态方法'''def...
python,decorator,class http://stackoverflow.com/questions/9906144/python-decorate-a-class-by-defining-the-decorator-as-a-class Apart from the question whether class decorators are the right solution to your problem: in Python 2.6 and higher, there are class decorators with the @-syntax, so you...
装饰器(decorator) Python装饰器的作用是使函数包装与方法包装(一个函数,接受函数并返回其增强函数)变得更容易阅读和理解。最初的使用场景是在方法定义的开头能够将其定义为类方法或静态方法。 不使用装饰器的代码如下所示 类方法不用装饰器的写法 class WithoutDecorators: ...
@decoratorclassPerson:def__init__(self,name):self.name=namedefsay_hello(self):print(f"Hello, my name is{self.name}.") 1. 2. 3. 4. 5. 6. 7. 上面的代码使用"@decorator"修饰符来修饰了"Person"类。修饰符将在类定义的时候被调用,并对类进行修饰。
def__call__(self):print('class decorator runing')self._func()print('class decorator ending')@Foo defbar():print('bar')bar() functools.wraps 使用装饰器极大地复用了代码,但是他有一个缺点就是原函数的元信息不见了,比如函数的docstring、__name__、参数列表,先看例子: ...
fromfunctoolsimportwrapsdefa_new_decorator(a_func): @wraps(a_func)defwrapTheFunction():print("I am doing some boring work before executing a_func()")a_func()print("I am doing some boring work after executing a_func()")returnwrapTheFunction@a_new_decoratordefa_function_requiring_decoration...