Warn about unreachable code

[bje-]

Current problem

It would be good if Pylint could warn about unreachable code like the raise below:

"""Example"""

for t in ['a', 'b', 'c', 'd']:
    if t in ['a', 'b', 'c', 'd']:
        pass
    else:
        raise ValueError

Desired solution

I would like a warning that the else is unreachable.

Additional context

No response

[DanielNoord]

This is likely never possible for pylint as there are too many moving parts.
I would suggest using something like coverage to track unused branches.

[Pierre-Sassoulas]

Blocked by #4795

[bje-]

Thanks -- I suspected as much. The issue is that I have an else raise ValueError branch to catch myself if I add a new list entry but no if case to match it. I don't really want to remove the else, so have no option but to mark it as 'no cover'.

[DanielNoord]

Thanks -- I suspected as much. The issue is that I have an else raise ValueError branch to catch myself if I add a new list entry but no if case to match it. I don't really want to remove the else, so have no option but to mark it as 'no cover'.

In personal projects I use raise AssertionError() and have that pattern be auto no cover in my coverage settings. That works quite well for such patterns.