False positive: calling super on bases base class is shown as error

[Bergiu]

Steps to reproduce

1. Make an empty folder and create the file test.py with this content:
   
2. pylint test.py

Current behavior

Executing the code works, but a false positive error is shown.

E1003: Bad first argument 'B' given to super() (bad-super-call)

Expected behavior

Pylint shouldn't show this error.

pylint --version output

astroid 2.2.5
Python 3.7.3 (default, Mar 26 2019, 21:43:19) 
[GCC 8.2.1 20181127]

[PCManticore]

@Bergiu At line 17 you are supposed to pass C to super(), not B. By passing Byou basically ask a MRO navigation starting from B instead of C for finding thesomething` method.

[Bergiu]

But I want it to start at B, so that I get the something method from A.

[Bergiu]

Can you reopen the issue @PCManticore, or am I getting something wrong?

[maxhillis]

What is the difference between lines 15 and 17? Why is 15 ok and 17 bad?

[Bergiu]

the method is called in line 17.

[maxhillis]

No sorry I mean from the perspective of pylint. If 17 is flagged then 15 should be too. I was trying to do the same thing you were and I couldn't understand why pylint considered this bad code. It works as I intend but I have been having trouble finding why its considered bad practice

[Bergiu]

Yes

[krystean]

Came across this while making a project which has the same structure as your code and can't understand why it's considered a bad-super-call. Isn't that the use of super?

[DanielNoord]

Re-opening this because we found ourselves that it is probably better to do consider this a false positive. If anybody feels like implementing this I think we would be more than happy to review and put this in one of the next releases!

For reference see the small discussion in:
pylint-dev/astroid#1217 (comment)

[cdce8p]

For reference and testing:

class Parent:
    def __init__(self):
        print("Parent")

class Child(Parent):
    def __init__(self):
        print("Child")
        super().__init__()

class GrandChild(Child):
    def __init__(self):
        print("Grandchild")
        super(Child, self).__init__()  # should not emit 'bad-super-call'!

GrandChild()

[cdce8p]

For reference: discussion about future usefulness of check: pylint-dev/astroid#1217 (comment)