@method_decorator() 源码解析

 # coding:utf-8
 """
 作用：
 原理：闭包 >> 1. 函数内部定义函数
              2.内部函数使用外部函数的变量
             3.外部函数返回内部函数的引用
 带参数的函数装饰器 》》 三层

 类的装饰器 >> 解决self 参数的问题
           >> 被装饰的对象是类不是函数
 """

 def method_decorator(decorator, name=''):
     print("类装饰器执行了")

     def _dec(cls):
         print("真正的类装饰器生成了，并执行了")
         is_class = isinstance(cls, type)
         if is_class:
             method = getattr(cls, name)
         else:
             raise Exception("该装饰器只用来装饰类")

         def _wrapper(self, *args, **kwargs):
             @decorator
             def bound_func(*args2, **kwargs2):
                 return method(self, *args2, **kwargs2)

             return bound_func(*args, **kwargs)

         setattr(cls, name, _wrapper)
         return cls

     return _dec

 def my_decorator(bound_func):
     print("函数装饰器执行了")

     def real_func(*args, **kwargs):
         print("\nexc decorator code before func\n")
         ret = bound_func(*args, **kwargs)
         print("\nexc decorator code after func\n")
         return ret

     return real_func

 """
 @method_decorator(decorator=my_decorator, name="get")
 ViewTemp = method_decorator(decorator=my_decorator, name="get")(ViewTemp)
 ViewTemp = _dec(ViewTemp)
 >>> ViewTemp.get = ViewTemp._wrapper
 """

 @method_decorator(decorator=my_decorator, name="get")
 class ViewTemp:
     def get(self, request):
         print("-----this is get method-----", "\nrequest==", request)

     def post(self, request):
         print("-----this is post method----")

 if __name__ == '__main__':
     """
     ViewTemp().get(request="xixixi)
     ViewTemp()._wrapper(request="xixixi)
     >>> _wrapper(self, request="xixixi)
     >>> >>> @decorator                                      my_decorator(bound_func)
     >>> >>> def bound_func(*args2, **kwargs2):              bound_func = real_func
                 return method(self, *args2, **kwargs2)
             return bound_func(*args, **kwargs)
     >>> real_func(request="xixixi)
     >>> >>> print("\nexc decorator code before func\n")
     >>> >>> ret = bound_func(request="xixixi") >> bound_func(request="xixixi") >> method(self, request="xixixi)
     >>> >>> print("\nexc decorator code after func\n")
     >>> >>> return ret

     """
     ViewTemp().get(request="xixixi")
     pass