{"record":{"id":"4a56051e8049656d","repo":"keras-team/keras","slug":"not-a-valid-gufunc-signature-signature","errorCode":null,"errorMessage":"not a valid gufunc signature: {signature}","messagePattern":"not a valid gufunc signature: (.+?)","errorType":"exception","errorClass":"ValueError","httpStatus":null,"severity":"error","filePath":"keras/src/backend/common/backend_utils.py","lineNumber":475,"sourceCode":"        )\n    return shifts, axes\n\n\n### Code for ops.vectorize() used for TF and torch backends.\n\n# See http://docs.scipy.org/doc/numpy/reference/c-api.generalized-ufuncs.html\n_DIMENSION_NAME = r\"\\w+\"\n_CORE_DIMENSION_LIST = \"(?:{0:}(?:,{0:})*)?\".format(_DIMENSION_NAME)\n_ARGUMENT = rf\"\\({_CORE_DIMENSION_LIST}\\)\"\n_ARGUMENT_LIST = \"{0:}(?:,{0:})*\".format(_ARGUMENT)\n_SIGNATURE = \"^{0:}->{0:}$\".format(_ARGUMENT_LIST)\n\n\ndef _vectorize_parse_gufunc_signature(\n    signature,\n):\n    if not re.match(_SIGNATURE, signature):\n        raise ValueError(f\"not a valid gufunc signature: {signature}\")\n    args, retvals = (\n        [\n            tuple(re.findall(_DIMENSION_NAME, arg))\n            for arg in re.findall(_ARGUMENT, arg_list)\n        ]\n        for arg_list in signature.split(\"->\")\n    )\n    return args, retvals\n\n\ndef _vectorize_update_dim_sizes(dim_sizes, shape, core_dims, is_input=True):\n    num_core_dims = len(core_dims)\n    if is_input:\n        if len(shape) < num_core_dims:\n            raise ValueError(\n                f\"input with shape {shape} does not \"\n                \"have enough dimensions for all core \"\n                f\"dimensions {core_dims}\"","sourceCodeStart":457,"sourceCodeEnd":493,"githubUrl":"https://github.com/keras-team/keras/blob/7a34a03db60bf60042242d6a556fc3be119046a5/keras/src/backend/common/backend_utils.py#L457-L493","documentation":"Error \"not a valid gufunc signature: {signature}\" thrown in keras-team/keras.","triggerScenarios":"Thrown at keras/src/backend/common/backend_utils.py:475 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":[],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"7a34a03db60bf60042242d6a556fc3be119046a5","analyzedAt":"2026-08-25T21:25:25.994Z","schemaVersion":2},"datasetVersion":"2026-08-26T02:17:13.382Z"}