Avoiding Flake8 Warnings on Boolean Comparisons in SQLAlchemy Filters

When working with SQLAlchemy, it's common to use boolean comparisons in filter clauses. However, flake8 may raise a warning when using the "==" operator for boolean comparisons.

Flake8's Recommendation

Flake8 suggests using "if cond is False:" or "if not cond:" instead of "if cond == False". This is generally good practice for python code in general.

SQLAlchemy Filter Behavior

However, in SQLAlchemy filter clauses, the "==" operator behaves differently. Using "==" to compare a field to False or True produces the expected filtering result.

Troubleshooting Filter Issues

If you encounter issues when using "is False" or "is not False" in filter clauses, it's important to remember that SQLAlchemy filters do not support these operators.

Handling the Situation

To resolve the issue and avoid disabling flake8, you can:

• Add a # noqa comment to the line in question.
• Use from sqlalchemy.sql.expression import false where false() returns the appropriate boolean value for your specific SQL dialect. This ensures the compatibility with SQLAlchemy filters.