Python函数的装饰器

def wrapper(fn):
    def inner(*args, **kwargs): # 聚合
        \"\"\"在目标函数之前的内容\"\"\"
        ret = fn(*arg, **kwargs) # 打散
        \"\"\"在目标函数之后的内容\"\"\"
        return ret
    return inner
@wrapper
def func():
    pass
func()

def wrapper1(fn):
    def inner(*args, **kwargs):
        print(\"1\")
        ret = fn(*args, **kwargs)
        print(\"2\")
        return ret
    return inner

def wrapper2(fn):
    def inner(*args, **kwargs):
        print(\"3\")
        ret = fn(*args, **kwargs)
        print(\"4\")
        return ret
    return inner

def wrapper3(fn):
    def inner(*args, **kwargs):
        print(\"5\")
        ret = fn(*args, **kwargs)
        print(\"6\")
        return ret
    return inner
# 顺序 1 2 3  func 3 2 1
@wrapper1
@wrapper2
@wrapper3
def func():
    print(\"我是谁,我在哪\")
func()  # 1 3 5 我是谁,我在哪 6 4 2

def wrapper_out(参数):
        def wrapper(fn):
            def inner(*args, **kwargs): # 聚合
                \"\"\"在目标函数之前的内容\"\"\"
                ret = fn(*arg, **kwargs) # 打散
                \"\"\"在目标函数之后的内容\"\"\"
                return ret
            return inner
        return wrapper
@wrapper_out(实参)  # 执行的时候. 先执行函数的调用然后使用返回值和前面的@组合成装饰器语法糖
def func():
    pass