Ruff and Flake8's McCabe complexity differs

[charliermarsh]

From Discord: https://gitlab.com/ppentchev/temp-20230302-ruff-complexity

[charliermarsh]

Reproduced.

[charliermarsh]

Here's a more minimal repro -- Ruff calls this 3, Flake8 calls this 2:

def process_detect_lines():
    try:
        pass
    finally:
        if res:
            errors.append(f"Non-zero exit code {res}")

I may have to actually learn how this works, because I thought that would've been 3.

[charliermarsh]

I guess it makes sense that it's 2 if you say that the finally has to trigger, but then why is this 2 also?

def process_detect_lines():
    try:
        pass
    finally:
        pass

[JonathanPlasse]

Maybe this is a bug in flake8.

[ashwinrajeev]

I guess it makes sense that it's 2 if you say that the finally has to trigger, but then why is this 2 also?

def process_detect_lines():
    try:
        pass
    finally:
        pass

I think this is a bug in flake8. This is supposed to be 1, not 2. Radon give this code 1 cc.

https://radon.readthedocs.io/en/latest/intro.html#cyclomatic-complexity

[charliermarsh]

Oh cool, I'll take another look at our implementation with those guidelines in mind.

[akx]

I also noticed this when adding Ruff to HA – didn't think to report it back then though! https://github.com/home-assistant/core/blob/fde205c158b704683650cec1d5832ca0858bbd21/pyproject.toml#L293-L302