Errors and warnings¶

polars_learn.PolarsLearnError¶

Base of package-specific processing and persistence errors.

Configuration TypeError/ValueError, scikit-learn NotFittedError, and native Polars/source exceptions are outside this hierarchy.

polars_learn.SchemaValidationError¶

Raised by SchemaValidator for learned schema or cast-policy failures.

Eager cast errors and Polars errors during explicitly requested collection preserve their causes. Lazy lossless integer-to-float checks can raise this at execution; permissive lazy cast failures can instead be native Polars errors. SchemaSpec uses ordinary ValueError for its explicit contract.

polars_learn.FeatureEngineeringError¶

Raised when feature planning, schema checks, or eager execution fail.

Wrapped expression/execution errors preserve their causes. Value-dependent failures in a returned lazy plan can be native Polars exceptions at query execution rather than this package exception.

polars_learn.PandasConversionWarning¶

Warning emitted on enabled pandas input conversion.

Controlled by warn_on_conversion, independently of verbosity. This is a UserWarning, not a PolarsLearnError.

polars_learn.InconsistentVersionWarning¶

class polars_learn.InconsistentVersionWarning(
    class_name,
    dependency,
    original_version,
    current_version,
)

A saved class is being restored with a different dependency version.

Attributes identify the class, dependency, original_version, and current_version. Loading is attempted unless the caller promotes this warning to an error. Silence accepted mismatches with warnings.simplefilter("ignore", InconsistentVersionWarning), preferably inside warnings.catch_warnings().

polars_learn.SerializationError¶

Signal that a model component could not be saved or restored.

Raised when expression serialization or saved-state restoration fails, including incompatible state after a dependency change. The original exception is retained as the cause so callers can inspect the failure. Catch this when reporting artifact loading/saving errors; a version mismatch alone emits InconsistentVersionWarning rather than this error.

polars_learn.ValueValidationError¶

Raised when a named row-level value check fails or cannot run.