Python:带有修饰符的函数的__qualname__ [英] Python: __qualname__ of function with decorator

问题描述

我正在另一个类的Instance方法中使用Decorator(类)，如下所示:

I'm using a Decorator (class) in an Instance method of another class, like this:

class decorator_with_arguments(object):

    def __init__(self, arg1=0, arg2=0, arg3=0):
        self.arg1 = arg1
        self.arg2 = arg2
        self.arg3 = arg3

    def __call__(self, f):
        print("Inside __call__()")
        def wrapped_f(*args):
            print(f.__qualname__)
            f(*args)
        return wrapped_f

class Lol:
    @decorator_with_arguments("hello")
    def sayHello(self,a1, a2, a3, a4):
        print(self.sayHello.__qualname__)

现在，当我打印出 self.sayHello .__ qualname __ 时，它会打印 decorator_with_arguments .__ call __.< locals> .wrapped_f

Now, when I print out self.sayHello.__qualname__ it prints decorator_with_arguments.__call__.<locals>.wrapped_f

有什么办法可以覆盖这个?我想在这里看到 Lol.sayHello (我的原始函数的质量名称).

Is there any way to override this? I want to see Lol.sayHello (qualname of my original function) in here.

我尝试覆盖 __ call __ 的 @property __ qualname __ (使用静态字符串)；没用.

I tried overriding the @property __qualname__ of __call__ (with a static string); didn't work.

推荐答案

您只需将 __ qualname __ 属性复制到您的 wrapped_f 包装函数中>;毕竟，应用装饰器时将返回此函数.

You can simply copy the __qualname__ attribute across to your wrapped_f wrapper function; it is this function that is returned when the decorator is applied, after all.

您可以使用 @ functools.wraps()装饰器为您完成此操作，以及note的其他属性:

You could use the @functools.wraps() decorator to do this for you, together with other attributes of note:

from functools import wraps

class decorator_with_arguments(object): 
    def __init__(self, arg1=0, arg2=0, arg3=0):
        self.arg1 = arg1
        self.arg2 = arg2
        self.arg3 = arg3

    def __call__(self, f):
        print("Inside __call__()")
        @wraps(f)
        def wrapped_f(*args):
            print(f.__qualname__)
            f(*args)
        return wrapped_f

那里的 @wraps(f)装饰器将相关属性从 f 复制到 wrapped_f ，包括 __ qualname __ :

The @wraps(f) decorator there copies the relevant attributes from f onto wrapped_f, including __qualname__:

>>> Lol.sayHello.__qualname__
'Lol.sayHello'

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