开发环境配置

装饰器

• 装饰器，是修改其他函数的功能的函数。

  在原函数不修改的基础上，对原函数功能进行扩展。

  无参装饰器

  def wrapper(main_func):
      def inner():
          print("login function called here.")
          main_func()
          print("log function called here.")
  
      return inner
  
  @wrapper
  def get_data():
      print("I am getting data...")
  
  
  # 调用方式
  get_data()

• *运行结果如下：**

  login function called here.
  I am getting data...
  log function called here.

运行过程分析：

1. get_data == wrapper(get_data) == inner
2. get_data()== inner()

有参装饰器

def wrapper(user, pwd):
    def outer(main_func):
        def inner(*args, **kwargs):
            print("login function called here.user=[%s],password=[%s]" % (user, pwd))
            main_func(*args, **kwargs)
            print("log function called here.")
        return inner

    return outer


@wrapper("gfc@126.com", "123456")
def get_data(*args, **kwargs):
    print("I am getting data...")
    print(args)
    print(kwargs)


# 调用方式
get_data("Milton", age=18)

运行结果如下：

login function called here.user=[gfc@126.com],password=[123456]
I am getting data...
('Milton',)
{'age': 18}
log function called here.

运行过程分析：

执行get_data(“Milton”,age=18)时：

get_data == wrapper("gfc@126.com","123456")(get_data)
         == outer(get_data)
         == inner
                          
get_data("Milton",age=18) == inner("Milton",age=18)

1. 先执行wrapper(“gfc@126.com“,”123456”), 返回outer函数

   def outer(main_func):
       def inner(*args, **kwargs):
           print("login function called here.user=[%s],password=[%s]" % (user, pwd))
           main_func(*args, **kwargs)
           print("log function called here.")
       return inner

2. 执行outer(get_data),返回inner函数

   def inner(*args, **kwargs):
       print("login function called here.user=[%s],password=[%s]" % (user, pwd))
       main_func(*args, **kwargs)
       print("log function called here.")

3. 执行inner(“Milton”,age=18)

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