Static abstract method link is not enforced while calling a class
Nobody has claimed this yet.
- Dominant language
- Python
- Stars
- 77.2k
- Forks
- 36k
- PR merge metrics
- PR metrics pending
Description
Bug report
If you define a method both static and abstract, for example in an interface like concept, you will expect that method to be implemented in all subclasses.
It works fine when calling instances of that child class, raising an exception if the static method is not implemented.
Also, IDE such as Pycharm will warn you that you are doing something fishy.
But you don't get an exception if you simply call the static method.
In the following example I would expect :
- to get an exception while calling Child telling me that this class is not implementing some method properly, such as method1.
- to get an exception while calling Parent static abstract method directly
from abc import ABC, abstractmethod
class Parent(ABC):
@staticmethod
@abstractmethod
def method1():
pass
@staticmethod
@abstractmethod
def method2():
print("Method 2 in Parent")
@abstractmethod
def method3(self):
pass
@abstractmethod
def method4(self):
print("Method 4 in Parent")
class Child(Parent):
@staticmethod
def method2():
print("Method 2 in Child")
def method4(self):
print("Method 4 in Child")
def test_abstract_class():
Parent.method1() # Should complain because calling an abstract class should be forbidden
Parent.method2() # Should complain because calling an abstract class should be forbidden
Child.method1() # Should complain because method was not defined
Child.method2()
print(issubclass(Child, Parent))
Your environment
Python 3.9 on windows 10
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start by reproducing the supplied Python 3.9 example and inspect the abc and abstract-method behavior involved in class and static-method calls. Compare the observed behavior with the two expected failure cases in the issue; done means the intended enforcement is implemented with regression tests covering Parent and Child.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- python
- Domain
- backend
- Issue type
- Bug
- Difficulty
- 5/5
- Estimated time
- Over a week
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 30/100