python3学习之装饰器

2020-01-03 10:52:13 浏览数 (1)

代码语言:javascript复制
#定义装饰器,outer参数是函数,返回也是函数
#作用:在函数执行前和执行后分别附加额外功能
def  outer(func):
    def  inner(*args, **kwargs):
        print("log")
        func(*args, **kwargs)
        print("Don't back")
        # return "r"
    return inner
@outer
def  f1(a):
    print(a,"F1")
@outer
def  f2(a,b):
    print("F2",a,b)
f1(123)
f2(123,456)


#带参数的装饰器,在outer外边又包装了一层
def oo(arg):
    print("hihihihi")    #此处的代码,在装饰器被调用时就被执行,不需要等被装饰的函数被调用
    def  outer(func):
        def  inner(*args, **kwargs):
            print(arg)
            print("log")
            func(*args, **kwargs)
            print("Don't back")
            print(arg)
            # return "r"
        return inner
    return outer
def  tt(func):
    def  inner(*args, **kwargs):
        # print(arg)
        print("aaaaa")
        func(*args, **kwargs)
        print("ttttt")
        # print(arg)
        # return "r"
    return inner
    
@tt
@oo(123333)   #可以多层装饰,规则是:从上到下执行装饰器
def  f1(a):
    print(a,"F1")

@oo(11111)
def  f2(a,b):
    print("F2",a,b)

#f1(123)
#f2(123,456)

结果:

hihihihi
hihihihi

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