{"record":{"id":"b1fba786ad715909","repo":"microsoft/qlib","slug":"subclass-of-instrumentstorage-must-implement-data","errorCode":null,"errorMessage":"Subclass of InstrumentStorage must implement `data` method","messagePattern":"Subclass of InstrumentStorage must implement `data` method","errorType":"exception","errorClass":"NotImplementedError","httpStatus":null,"severity":"error","filePath":"qlib/data/storage/storage.py","lineNumber":49,"sourceCode":"        ------\n        ValueError\n            If the data(storage) does not exist, raise ValueError\n        '''\n        raise NotImplementedError(\"Subclass of CalendarStorage must implement `data` method\")\n\n\nclass UserInstrumentStorage(InstrumentStorage):\n\n    @property\n    def data(self) -> Dict[InstKT, InstVT]:\n        '''get all data\n\n        Raises\n        ------\n        ValueError\n            If the data(storage) does not exist, raise ValueError\n        '''\n        raise NotImplementedError(\"Subclass of InstrumentStorage must implement `data` method\")\n\n\nclass UserFeatureStorage(FeatureStorage):\n\n    def __getitem__(self, s: slice) -> pd.Series:\n        '''x.__getitem__(slice(start: int, stop: int, step: int)) <==> x[start:stop:step]\n\n        Returns\n        -------\n            pd.Series(values, index=pd.RangeIndex(start, len(values))\n\n        Notes\n        -------\n        if data(storage) does not exist:\n            if isinstance(i, int):\n                return (None, None)\n            if isinstance(i,  slice):\n                # return empty pd.Series","sourceCodeStart":31,"sourceCodeEnd":67,"githubUrl":"https://github.com/microsoft/qlib/blob/79633dd9506ea689e5400dea0197717b5b3d74b7/qlib/data/storage/storage.py#L31-L67","documentation":"Error \"Subclass of InstrumentStorage must implement `data` method\" thrown in microsoft/qlib.","triggerScenarios":"This error is raised at qlib/data/storage/storage.py:49 when the guard condition fails: \"Subclass of InstrumentStorage must implement `data` method\". It triggers when the code path receives input or a state that violates the precondition checked at this point — e.g. an unimplemented abstract method being called, an unsupported argument type/value, or an invalid configuration. To avoid it, satisfy the documented precondition before this call: implement the required method in your subclass, or pass a supported value of the expected type as described by the message.","commonSituations":"See trigger scenarios.","solutions":["Implement the `data` method in your InstrumentStorage subclass.","Use the built-in FileInstrumentStorage which implements `data`."],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"79633dd9506ea689e5400dea0197717b5b3d74b7","analyzedAt":"2026-08-15T07:01:27.511Z","schemaVersion":2},"datasetVersion":"2026-08-15T17:31:12.345Z"}