pandas.errors.SpecificationError

exceptionpandas.errors.SpecificationError[source]

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.

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