Python之第三十五天的努力--带参数的装饰器

带参数的装饰器

• 版本一：写了很多函数，添加日志： 在 什么时间 调用了什么函数

  import time
  
  def log(func):
      def inner(*args,**kwargs):
          ret = func(*args,**kwargs)
          print(f'{time.strftime("%Y-%m-%d %H:%M:%S")} 执行了{func.__name__}')
          return ret
      return inner
  
  @log
  def login():
      print('登录')
  
  @log
  def register():
      print('注册')
  
  @log
  def show_goods():
      print('查看所有商品信息')
  
  @log
  def add_goods():
      print('商品加入购物车')
  
  login()     # 2020-07-20 13:14:25 执行了login
  

• 版本二：登录和注册的信息 写到 auth.log文件里，所有的购物信息 写到operate.log文件里

  import time
  
  def log(func):
      def inner(*args,**kwargs):
          ret = func(*args,**kwargs)
          if func.__name__ == 'login' or func.__name__ == 'register':
              with open('auth.log',encoding='utf-8',mode='a')as f1:
                  msg = f'{time.strftime("%Y-%m-%d %H:%M:%S")} 执行了{func.__name__}'
                  f1.write(msg)
          else:
              with open('operate.log',encoding='utf-8',mode='a')as f2:
                  msg = f'{time.strftime("%Y-%m-%d %H:%M:%S")} 执行了{func.__name__}'
                  f2.write(msg)
          return ret
      return inner
  
  @log
  def login():
      print('登录')
  
  @log
  def register():
      print('注册')
  
  @log
  def show_goods():
      print('查看所有商品信息')
  
  @log
  def add_goods():
      print('商品加入购物车')
  
  login()
  add_goods()
  

• 版本三：

  import time
  
  def logger(path):
      def log(func):
          def inner(*args,**kwargs):
              ret = func(*args,**kwargs)
              with open(path,encoding='utf-8',mode='a')as f1:
                  msg = f'{time.strftime("%Y-%m-%d %H:%M:%S")} 执行了{func.__name__}\n'
                  f1.write(msg)
              return ret
          return inner
      return log
  
  @logger('auth.log')
  def login():
      print('登录')
  # @logger('auth.log') ---> ret = logger('auth.log')
  # ---> @ret   ---> login = ret(login)
  
  # @logger('auth.log') ---> logger('auth.log')返回一个log --->@log
  
  @logger('auth.log')
  def register():
      print('注册')
  
  @logger('operate.log')
  def show_goods():
      print('查看所有商品信息')
  
  @logger('operate.log')
  def add_goods():
      print('商品加入购物车')
  
  login()
  add_goods()
  

• 精髓：

  # 原本有个装饰器wrapper
  # def wrapper(func):
  #     def inner():
  #         pass
  #     return inner
  
  # 需要
  # @wrapper
  # def func():
  #     pass
  # ----->
  # @xxx('参数')
  # def func():
  #   pass
  
  # 则，把原来的装饰器改为： 
  # def xxx(*args):
  #   def wrapper(func):
  #     def inner():
  #         pass
  #     return inner
  #   return wrapper