{"record":{"id":"4ea0d05de7024dda","repo":"freqtrade/freqtrade","slug":"duplicate-column-name-date-column-exists-in-data","errorCode":null,"errorMessage":"Duplicate column name {date_column} exists in dataframe! Ensure column names are unique!","messagePattern":"Duplicate column name (.+?) exists in dataframe! Ensure column names are unique!","errorType":"exception","errorClass":"OperationalException","httpStatus":null,"severity":"error","filePath":"freqtrade/strategy/informative_decorator.py","lineNumber":309,"sourceCode":"        formatter = fmt  # A custom user-specified formatter function.\n    else:\n        formatter = fmt.format  # A default string formatter.\n\n    fmt_args: dict[str, str] = {\n        **__get_pair_formats(market),\n        \"asset\": asset,\n        \"timeframe\": timeframe,\n    }\n    cache_enabled = cache is not None\n    inf_dataframe = inf_dataframe.rename(\n        columns=lambda column: _format_informative_column(\n            column, formatter, fmt_args, preserve_date_merge=cache_enabled\n        )\n    )\n\n    date_column = _format_informative_column(\"date\", formatter, fmt_args)\n    if date_column in dataframe.columns:\n        raise OperationalException(\n            f\"Duplicate column name {date_column} exists in \"\n            f\"dataframe! Ensure column names are unique!\"\n        )\n    if cache_enabled:\n        dataframe = _merge_prepared_informative_pair(\n            dataframe,\n            _PreparedInformative(inf_dataframe, _INFORMATIVE_DATE_MERGE),\n            ffill=inf_data.ffill,\n        )\n    else:\n        dataframe = merge_informative_pair(\n            dataframe,\n            inf_dataframe,\n            strategy.timeframe,\n            timeframe1,\n            ffill=inf_data.ffill,\n            append_timeframe=False,\n            date_column=date_column,","sourceCodeStart":291,"sourceCodeEnd":327,"githubUrl":"https://github.com/freqtrade/freqtrade/blob/1c8edfe4d1e8d11bd4b40e8fc3237c26c3a60e15/freqtrade/strategy/informative_decorator.py#L291-L327","documentation":"Error \"Duplicate column name {date_column} exists in dataframe! Ensure column names are unique!\" thrown in freqtrade/freqtrade.","triggerScenarios":"Thrown at freqtrade/strategy/informative_decorator.py:309 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":["Use unique column names across merged informative dataframes; add distinct suffixes via the informative() decorator.","Rename the conflicting column in one of the informative definitions."],"exampleFix":"Check for duplicate columns before merge:\nif date_column in dataframe.columns:\n    raise OperationalException(f'Duplicate column name {date_column} exists in dataframe! Ensure column names are unique!')","handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"1c8edfe4d1e8d11bd4b40e8fc3237c26c3a60e15","analyzedAt":"2026-08-15T05:09:08.096Z","schemaVersion":2},"datasetVersion":"2026-08-15T22:17:37.221Z"}