E712 (Comparison to True should be cond is True) should be ignored when comparison is against pandas.Series

[rsokolewicz]

using ruff==0.0.215

The following snippet raises an E712 when running ruff:

import pandas as pd

df = pd.DataFrame({"x" : [False, True]})
df["x"] != False

and the autofix replaces df["x"] != False with df["x"] is not False. The two are unfortunately not equivalent and the latter leads to errors from pandas.

[charliermarsh]

Pretty hard to avoid until we can infer that df is a DataFrame here.

[akanz1]

Can we prevent the autofix from applying this specific rule?

[nils-borrmann-y42]

The same problem happens in sqlalchemy queries (.where(foo != bar) is not equivalent to .where(foo is not bar))

[charliermarsh]

Before I disable autofix for this rule entirely... you can disable it for your project via:

[tool.ruff]
unfixable = ["E712"]

Is that sufficient here?

[akanz1]

Works for me, thanks! :)

[rsokolewicz]

In my data analysis and data science projects I end up ignoring this rule more often than having it autofixed, so I ended up using

[tool.ruff]
ignore = ["E712"]

instead. There are a few other cases where autofixing == True to is True will break code, namely when comparing against booleans that have a package-specific implementation such as numpy (numpy.bool_) or pytorch (toch.bool).

[charliermarsh]

Yeah, that makes sense. I think I'm going to close this for now given that we have some workarounds (users should either disable the rule entirely, or, if they want the rule to be enabled but want to avoid false fixes, should use unfixable).

[Faolain]

This just broke our code using SQLAlchemy converting

signup_code = (
    db.session.query(SignupCode)
    .filter(SignupCode.code == code, SignupCode.used == False)
    .first()
)

to

 signup_code = (
        db.session.query(SignupCode)
        .filter(SignupCode.code == code, SignupCode.used is False)
        .first()
    )

which it definitely shouldn't have autofixed. Can this instead be a suggestion provided but something that is not autofixed? Can prevent a lot of headaches.

[charliermarsh]

This is marked in the codebase as a "Suggested" autofix, which in a future release will require running with additional command-line flags to explicitly opt-in to fixing.