{"record":{"id":"b542aa314d90dbb2","repo":"pola-rs/polars","slug":"the-argument-param-name-r-for-func-name-r-was-b542aa","errorCode":null,"errorMessage":"the argument {param.name!r} for {func_name!r}{was_deprecated_and} has been removed in version {param.removed_in}.","messagePattern":"the argument (.+?) for (.+?)(.+?) has been removed in version (.+?)\\.","errorType":"exception","errorClass":"ArgumentRemovedError","httpStatus":null,"severity":"error","filePath":"py-polars/src/polars/_utils/expired.py","lineNumber":158,"sourceCode":"                f\" {param.name!r}{was_deprecated_and} has been renamed to\"\n                f\" {param.new_name!r} in version {param.removed_in}.\"\n            )\n            raise ArgumentRemovedError(msg)\n        else:\n            msg = (\n                f\"the argument {param.name!r} for {func_name!r}{was_deprecated_and}\"\n                f\" has been removed in version {param.removed_in}.\"\n                f\" It was renamed to {param.new_name!r}.\"\n            )\n            msg = msg if param.hint is None else f\"{msg} {param.hint}\"\n            raise ArgumentRemovedError(msg)\n    elif isinstance(param, RemovedParameter):\n        msg = (\n            f\"the argument {param.name!r} for {func_name!r}{was_deprecated_and}\"\n            f\" has been removed in version {param.removed_in}.\"\n        )\n        msg = msg if param.hint is None else f\"{msg} {param.hint}\"\n        raise ArgumentRemovedError(msg)\n    else:\n        msg = f\"Unexpected parameter type: {type(param)!r}\"\n        raise TypeError(msg)\n","sourceCodeStart":140,"sourceCodeEnd":162,"githubUrl":"https://github.com/pola-rs/polars/blob/5d8ebabf11caea54a5c29178a64a058762f49766/py-polars/src/polars/_utils/expired.py#L140-L162","documentation":"Raised when a decorated polars function receives a parameter that was removed outright (not renamed). The message names the parameter, function, removal version, and an optional hint about what to do instead.","triggerScenarios":"Passing a removed kwarg such as strict=False to functions where it was dropped, or copy=... where the option no longer exists — any RemovedParameter registered with the decorator's removed_parameters.","commonSituations":"Post-upgrade breakage where an option was eliminated because the behavior became unconditional or contradictory; code copied from old docs.","solutions":["Remove the argument from the call","Read the hint in the error for the recommended alternative behavior","Check the function's current signature via help() or the migration guide"],"exampleFix":"# before\npl.concat([df1, df2], how='horizontal', strict=False)\n# after\npl.concat([df1, df2], how='horizontal_extend')","handlingStrategy":"validation","validationCode":"REMOVED = {'strict': 'horizontal_extend', 'copy': None}\nfor k in list(kwargs):\n    if k in REMOVED:\n        del kwargs[k]  # or apply documented alternative","typeGuard":null,"tryCatchPattern":null,"preventionTips":["Read the removal hint in the error and apply the alternative","Track polars release notes for removed options","Avoid carrying unused legacy options in shared config dicts"],"tags":["python","polars","removed-parameter","migration","kwargs"],"backgroundTag":"removed-parameter","analyzedSha":"5d8ebabf11caea54a5c29178a64a058762f49766","analyzedAt":"2026-08-28T18:02:35.179Z","contentChangedAt":"2026-08-28T18:02:35.179Z","schemaVersion":2},"datasetVersion":"2026-09-14T00:17:10.932Z"}