{"record":{"id":"4244e452f1928b3e","repo":"pola-rs/polars","slug":"fill-null-strategy-is-not-supported","errorCode":null,"errorMessage":"fill-null strategy {:?} is not supported","messagePattern":"fill-null strategy (.+?) is not supported","errorType":"exception","errorClass":"PolarsError::InvalidOperation","httpStatus":null,"severity":"error","filePath":"crates/polars-core/src/chunked_array/ops/fill_null.rs","lineNumber":403,"sourceCode":"        FillNullStrategy::One => ca.fill_null_with_values(true).map(|ca| ca.into_series()),\n        FillNullStrategy::Zero => ca.fill_null_with_values(false).map(|ca| ca.into_series()),\n        FillNullStrategy::Forward(_) => unreachable!(),\n        FillNullStrategy::Backward(_) => unreachable!(),\n    }\n}\n\nfn fill_null_binary(ca: &BinaryChunked, strategy: FillNullStrategy) -> PolarsResult<BinaryChunked> {\n    match strategy {\n        FillNullStrategy::Min => {\n            ca.fill_null_with_values(ca.min_binary().ok_or_else(err_fill_null)?)\n        },\n        FillNullStrategy::Max => {\n            ca.fill_null_with_values(ca.max_binary().ok_or_else(err_fill_null)?)\n        },\n        FillNullStrategy::Zero => ca.fill_null_with_values(&[]),\n        FillNullStrategy::Forward(_) => unreachable!(),\n        FillNullStrategy::Backward(_) => unreachable!(),\n        strat => polars_bail!(InvalidOperation: \"fill-null strategy {:?} is not supported\", strat),\n    }\n}\n\nimpl<T> ChunkFillNullValue<T::Native> for ChunkedArray<T>\nwhere\n    T: PolarsNumericType,\n{\n    fn fill_null_with_values(&self, value: T::Native) -> PolarsResult<Self> {\n        Ok(self.apply_kernel(&|arr| Box::new(set_at_nulls(arr, value))))\n    }\n}\n\nimpl ChunkFillNullValue<bool> for BooleanChunked {\n    fn fill_null_with_values(&self, value: bool) -> PolarsResult<Self> {\n        self.set(&self.is_null(), Some(value))\n    }\n}\n","sourceCodeStart":385,"sourceCodeEnd":421,"githubUrl":"https://github.com/pola-rs/polars/blob/9b5d73fd00236295624374b075d16b1fe6ec6df9/crates/polars-core/src/chunked_array/ops/fill_null.rs#L385-L421","documentation":"todo!/unreachable-style panic arm in the fill_null strategy dispatch for a dtype with no fill strategy implemented (the match fell through). The requested FillNullStrategy is unsupported for that column's type in this build; use a different strategy or fill via expression.","triggerScenarios":"This panic/expect fires when execution reaches an unguarded state described by: \"fill-null strategy {:?} is not supported\". Typical triggers: unsupported dtype or feature-gated code path reached at runtime, invalid user input or environment variable value, calling API methods in the wrong order or on mismatched types, or data (lengths, offsets, ranges) violating the function's preconditions.","commonSituations":"Encountered when input data or configuration does not meet the preconditions of the throwing code path (\"fill-null strategy {:?} is not supported\"). Common cases: missing Cargo feature flags, mismatched dtypes/lengths between arrays or series, out-of-range temporal values, malformed environment variables, or operations on unsupported/complex nested types.","solutions":["Use a supported FillNullStrategy: Forward, Backward, Mean, Min, Max, Zero, One, or a literal value.","For unsupported strategies on this dtype, cast the column first or implement the fill manually."],"exampleFix":null,"handlingStrategy":"fallback","validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"9b5d73fd00236295624374b075d16b1fe6ec6df9","analyzedAt":"2026-08-19T12:15:06.350Z","contentChangedAt":"2026-08-19T12:15:06.350Z","schemaVersion":2},"datasetVersion":"2026-09-14T00:17:10.932Z"}