This issue tracker has been migrated to GitHub, and is currently read-only.
For more information, see the GitHub FAQs in the Python's Developer Guide.

Author erezinman
Recipients erezinman
Date 2021-01-23.14:26:11
SpamBayes Score -1.0
Marked as misclassified Yes
Message-id <1611411971.69.0.738980453065.issue43010@roundup.psfhosted.org>
In-reply-to
Content
Consider the following code:

```
from abc import ABC, abstractmethod
from functools import wraps

class A(ABC):
    @abstractmethod
    def f(self):
        pass
    
    @wraps(f)
    def wrapper(self):
        print('f is called!')
        f()
        
class B(A):
    def f(self):
        print('f!')

B()
```

The last line of code results in the following error:
>>> TypeError: Can't instantiate abstract class B with abstract methods wrapper

That happens because `wraps` copies the `__dict__` of the original function. The problem is that at the point of declaration, the `__dict__` also contained `__isabstractmethod__=True` so it was copied as well, and it caused an error on the class' instantiation even though it contained no abstract methods. 
Moreover, this behavior is misleading because the the wrapper function is not abstract. 

Thanks.
History
Date User Action Args
2021-01-23 14:26:11erezinmansetrecipients: + erezinman
2021-01-23 14:26:11erezinmansetmessageid: <1611411971.69.0.738980453065.issue43010@roundup.psfhosted.org>
2021-01-23 14:26:11erezinmanlinkissue43010 messages
2021-01-23 14:26:11erezinmancreate