python中wraps作用

functools.wraps 的作用是将原函数对象的指定属性复制给包装函数对象, 默认有 module、name、doc,或者通过参数选择。

import functoolsdef itcast1(fun):# 带参数的装饰器#wraps是用来将inner函数的属性设置为fun的属性值&＃64;functools.wraps(fun)def inner(*args, **kwargs):print("itcast1 start")fun(*args, **kwargs)print("itcast1 end")return inner


上述代码可表示为&＃xff1a;

# def itcast1(fun):#     def inner(*args, **kwargs):#        print("itcast1 start")#        fun(*args, **kwargs)#        print("itcast1 end")#    inner.__name__ &＃61; fun.__name__#    inner.__doc__ &＃61; fun.__doc__#     return inner

>>> &＃64;itcast1
... def say_hello():
... print(&＃39;say_hello&＃39;)
...
>>> print(say_hello.__name__)
say_hello


若itcast1中没有使用wraps&＃xff1a;

>>> def itcast1(fun):
... def inner(*args, **kwargs):
... print(&＃39;itcast1 start&＃39;)
... fun(*args, **kwargs)
... print("itcast1 end")
... return inner
...
>>> &＃64;itcast1
... def say_hello():
... print(&＃39;say_hello&＃39;)
...
>>> print(say_hello.__name__)
inner
>>> say_hello()
itcast1 start
say_hello
itcast1 end