• Python 学习之路


    装饰器

    装饰器也是函数,用于被装饰函数执行时,增加被装饰函数的功能。

     1 def decor(func):
     2     def warpper(*args,**kwargs):
     3         print("Welcome!")
     4         func(*args,**kwargs)
     5         print("*-------------*")
     6     return warpper
     7 
     8 
     9 @decor
    10 def simple(name):
    11     print(name)
    12 
    13 simple("ChangDu")
    import time
    
    def timmer(func):
        def warpper(*args,**kwargs):
            start_time=time.time()
            func(*args,**kwargs)
            stop_time=time.time()
            print("The running time:%s"%(stop_time-start_time))
        return warpper
    
    # @ + 函数名
    # 1. 自动执行timmer函数并将下面的函数名test1当做参数传递
    # 2. 将timmer函数的返回值重新赋值给test1
    @timmer #test1=timmer(test1)
    def test1(name,ss):#一旦一个函数被装饰,这个函数就会被赋值成装饰函数的内层函数
        time.sleep(3)
        print("test")
        print(name,ss)
    
    test1("amy",ss="uu")
    被装饰函数的不同参数传给装饰器
    db_user_name,db_password= "amy" , "123"
    
    def auth(func):
        print("----",func)
        def warpper(*args,**kwargs):
            user_name=input("UserName:").strip()
            password=input("Password:").strip()
            if db_user_name==user_name and db_password==password:
                r = func()
                print("hhhh")
                return r
            else:
                print("Error")
        return warpper
    
    
    
    def index():
        print("welcome to index page")
    
    @auth
    def home():
        print("welcome to home page")
        return "welcome"
    
    @auth
    def bbs():
        print("welcome to bbs page")
    
    
    index()
    print(home())
    bbs()
    装饰器返回被装饰函数执行后的值
    name,password="amy","123"
    def auth(way):
        def outer(func):
            def wrapper(*args,**kwargs):
                if way == "local":
                    user_name=input("UserName:").strip()
                    user_password=input("Password:").strip()
                    if user_name==name and user_password==password:
                        print("Welcome------local")
                        r=func()
                        print("End")
                        return r
                    else:
                        print("Error")
                elif way == "other":
                    print("forget it-----other")
                    r = func()
                    return r
            return wrapper
        return outer
    
    
    def index():
        print("Welcome to index")
    
    
    @auth(way="local")
    def home():
        print("Welcome to home")
        return True
    
    
    @auth(way="other")
    def bbs():
        print("Welcome to bbs")
    
    index()
    print(home())
    bbs()
    三层装饰器
    def outer(func):
        def warpper(*args,**kwargs):
            print("1")
            r = func(*args,**kwargs)
            return r
        return warpper
    
    
    def outer2(func):
        def warpper(*args,**kwargs):
            print("2")
            r = func(*args,**kwargs)
            return r
        return warpper
    
    @outer
    @outer2
    def f1():
        print("test")
    
    f1()
    多个装饰器装饰一个函数
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  • 原文地址:https://www.cnblogs.com/peiling-wu/p/6528011.html
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