一、装饰器装饰类方法

from functools import wrapsdef wrapper(func):    @wraps(func)    def inner(self,*args,**kwargs):        # 此时的self是Person的实例对象        self.name += "爱吃糖"        # func ===>  printInfo        ret = func(self,*args,**kwargs)        return ret    return innerclass Person(object):    def __init__(self,name):        self.name = name    @wrapper    def printInfo(self):        print(self.name)# printInfo ==> wraper(printInfo) ==> innerPerson("张三").printInfo()# 张三爱吃糖

二、类装饰器实现单例模式

def wrapper(obj):    def inner(name,*args,**kwrags):        if not obj.instance:            obj.instance = obj(name)        return obj.instance    return inner@wrapperclass Person(object):    instance = None    def __init__(self,name):        self.name = name    def printInfo(self):        print(self.name)zs = Person('张三')zs.printInfo()print(id(zs))ls = Person('李四')ls.printInfo()print(id(ls))

三、给装饰器写log

import timefrom functools import wrapsdef log(func):    @wraps(func)    def inner(fun,*args,**kwargs):        print("%s执行了"%(func))        ret = func(fun)        return ret    return inner@logdef wraper(func):    @wraps(func)    def inner(*args,**kwargs):        start_time = time.time()        ret = func()        endtime = time.time() - start_time        print(endtime)        return ret    return inner@wraperdef func():    time.sleep(5)    print("func执行了")# wraper(func) ==>log(wraper) ==>inner# func() ==> wraper(func)==>innerfunc()