一. 我们先写一个玩游戏的步骤

# def play():
#     print(\"双击LOL\")
#     print(\"选择狂战士\")
#     print(\"进草丛\")
#     print(\"崩山击\",\"十字斩\")
我们想添加
  1.开挂
  2.关闭外挂
  目标函数前和后插入一段新代码 不改变原来代码
# def wrapper(fn):
#     def inner():
#         print(\"开挂\")
#         fn()
#         print(\"关闭外挂\")
#     return inner
#
# play = wrapper(play)
#
# play()

通用装饰器的语法:

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()

 

同一个函数被多个装饰器装饰

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(\"装饰器不难  滑稽脸)\")
func()  # 1 3 5 装饰器不难  滑稽脸 6 4 2

带参数的装饰器

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

 

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