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# pandas.errors.SpecificationError

exception pandas.errors.SpecificationError

  Exception raised by `agg` when the functions are ill-specified.

  The exception raised in two scenarios.

  The first way is calling `agg` on a Dataframe or Series using a nested renamer (dict-of-dict).

  The second way is calling `agg` on a Dataframe with duplicated functions names without assigning column name.

  See also

  `DataFrame.agg`

    Aggregate using one or more operations over the specified axis.

  `Series.agg`

    Aggregate using one or more operations over the specified axis.

  Examples

      >>> df = pd.DataFrame({"A": [1, 1, 1, 2, 2], "B": range(5), "C": range(5)})
      >>> df.groupby("A").B.agg({"foo": "count"})
      ... # SpecificationError: nested renamer is not supported

      >>> df.groupby("A").agg({"B": {"foo": ["sum", "max"]}})
      ... # SpecificationError: nested renamer is not supported

      >>> df.groupby("A").agg(["min", "min"])
      ... # SpecificationError: nested renamer is not supported