{"record":{"id":"d182c321594ce0e2","repo":"microsoft/qlib","slug":"subclass-of-instrumentstorage-must-implement-de","errorCode":null,"errorMessage":"Subclass of InstrumentStorage must implement `__delitem__` method","messagePattern":"Subclass of InstrumentStorage must implement `__delitem__` method","errorType":"exception","errorClass":"NotImplementedError","httpStatus":null,"severity":"error","filePath":"qlib/data/storage/storage.py","lineNumber":237,"sourceCode":"\n            In either case, this is followed by: for k, v in F.items(): D[k] = v\n\n        \"\"\"\n        raise NotImplementedError(\"Subclass of InstrumentStorage must implement `update` method\")\n\n    def __setitem__(self, k: InstKT, v: InstVT) -> None:\n        \"\"\"Set self[key] to value.\"\"\"\n        raise NotImplementedError(\"Subclass of InstrumentStorage must implement `__setitem__` method\")\n\n    def __delitem__(self, k: InstKT) -> None:\n        \"\"\"Delete self[key].\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 `__delitem__` method\")\n\n    def __getitem__(self, k: InstKT) -> InstVT:\n        \"\"\"x.__getitem__(k) <==> x[k]\"\"\"\n        raise NotImplementedError(\"Subclass of InstrumentStorage must implement `__getitem__` method\")\n\n    def __len__(self) -> int:\n        \"\"\"\n\n        Raises\n        ------\n        ValueError\n            If the data(storage) does not exist, raise ValueError\n\n        \"\"\"\n        raise NotImplementedError(\"Subclass of InstrumentStorage must implement `__len__`  method\")\n\n\nclass FeatureStorage(BaseStorage):","sourceCodeStart":219,"sourceCodeEnd":255,"githubUrl":"https://github.com/microsoft/qlib/blob/79633dd9506ea689e5400dea0197717b5b3d74b7/qlib/data/storage/storage.py#L219-L255","documentation":"Error \"Subclass of InstrumentStorage must implement `__delitem__` method\" thrown in microsoft/qlib.","triggerScenarios":"This error is raised at qlib/data/storage/storage.py:237 when the guard condition fails: \"Subclass of InstrumentStorage must implement `__delitem__` 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 `__delitem__` method in your InstrumentStorage subclass.","Use the built-in FileInstrumentStorage which implements `__delitem__`."],"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":"2026-08-15T22:17:37.221Z"}