fix for missing types on NamedAgg (#111)

Author: bschnurr

pandas/_typing.pyi

@@ -42,6 +42,14 @@ T = TypeVar('T')
 FuncType = Callable[..., Any]
 F = TypeVar("F", bound=FuncType)
 
+AggFuncTypeBase = Union[Callable, str]
+AggFuncTypeDict = Dict[Hashable, Union[AggFuncTypeBase, List[AggFuncTypeBase]]]
+AggFuncType = Union[
+    AggFuncTypeBase,
+    List[AggFuncTypeBase],
+    AggFuncTypeDict,
+]
+
 num = Union[int, float]
 SeriesAxisType = Union[str, int, Literal["index", 0]]  # Restricted subset of _AxisType for series
 AxisType = Union[str, int, Literal["columns", "index", 0, 1]]

pandas/core/groupby/generic.pyi

@@ -1,7 +1,7 @@
 from matplotlib.axes import Axes as PlotAxes, SubplotBase as AxesSubplot
 import numpy as np
 import sys
-from pandas._typing import FrameOrSeries as FrameOrSeries, AxisType, Dtype, Level, F
+from pandas._typing import FrameOrSeries as FrameOrSeries, AxisType, Dtype, Level, F, AggFuncType
 from pandas.core.frame import DataFrame as DataFrame
 from pandas.core.groupby.groupby import GroupBy as GroupBy #, get_groupby as get_groupby
 from pandas.core.groupby.grouper import Grouper as Grouper
@@ -13,8 +13,8 @@ else:
     from typing_extensions import Literal
 
 class NamedAgg(NamedTuple):
-    column = ...
-    aggfunc = ...
+    column: str = ...
+    aggfunc: AggFuncType = ...
 
 AggScalar = Union[str, Callable[..., Any]]
 ScalarResult = ...