class CACHE_Decorator: def __init__(self, func) -> None: self.func = func self.cache = {} def __call__(self, *args: Any, **kwds: Any) -> Any: if args in self.cache: return self.cache[args] else: ret = self.func(
Decorator 所实现的功能就是修改紧接 Decorator 之后定义的函数和方法。这总是可能的,但这种功能主要是由 Python 2.2 中引入的classmethod() 和staticmethod() 内置函数驱动的。在旧式风格中,您可以调用 classmethod(),如下所示: 清单1. 典型的 “旧式” classmethod class C: def foo(cls, y): print "classmeth...
*args, **kws): print what return meth(self, *args, **kws) return new return what_sayerdef FooMaker(word): class Foo(object): @arg_sayer(word) def say(self): pass return Foo()foo1 = FooMaker('this')foo2 = FooMaker('that')print type(foo1),; foo1.s...
(myfun.__name__) print(myfun.__doc__) In the example, we apply the @wraps decorator on the wrapper function. The name and the docstring of the original function (myfun) are kept. $ python main.py *** myfun *** myfun this is myfun() The class decorator It possible...
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...
我之前在《理解Python的装饰器(decorators)Part 1》里面讲到过,装饰器可以分为两大类,一种是decorating function装饰函数,还有一种是装饰类decorating class。之前我所用到的例子都是function decorator。这里就讲讲class decorator。与function decorator类似,class decorator也是一个函数(或者可调用对象callable object): ...
class as decorator """ importtime classA: def__init__(self, func): print"__init__" def__call__(self): time.sleep(10) print"__call__" @A deftest():#编译器将把这里解释为 instanceA = A(test), 当我们调用test的时候实际上调用的是instanceA (*args),即instanceA.__call__(*args)...
class Circle: #半径用下划线开头,表示私有变量 def __init__(self, radius): self._radius = radius #用property装饰器创建虚拟的半径属性 @property def radius(self): return self._radius #用setter装饰器给半径属性添加赋值操作 @radius.setter def radius(self, value): if value >= 0: self._radius...
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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: