Message385538
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. |
|
Date |
User |
Action |
Args |
2021-01-23 14:26:11 | erezinman | set | recipients:
+ erezinman |
2021-01-23 14:26:11 | erezinman | set | messageid: <1611411971.69.0.738980453065.issue43010@roundup.psfhosted.org> |
2021-01-23 14:26:11 | erezinman | link | issue43010 messages |
2021-01-23 14:26:11 | erezinman | create | |
|