Tidy resample type hints

Author: oliverhiggs

xarray/core/common.py

@@ -28,6 +28,9 @@
 except ImportError:
     cftime = None
 
+if TYPE_CHECKING:
+    from xarray.core.types import ResampleCompatible
+
 # Used as a sentinel value to indicate a all dimensions
 ALL_DIMS = ...
 
@@ -890,7 +893,7 @@ def rolling_exp(
     def _resample(
         self,
         resample_cls: type[T_Resample],
-        indexer: Mapping[Hashable, str | Resampler] | None,
+        indexer: Mapping[Hashable, ResampleCompatible | Resampler] | None,
         skipna: bool | None,
         closed: SideOptions | None,
         label: SideOptions | None,
@@ -1077,7 +1080,7 @@ def _resample(
         )
 
         grouper: Resampler
-        if isinstance(freq, str | datetime.timedelta | pd.Timedelta | pd.DateOffset):
+        if isinstance(freq, ResampleCompatible):
             grouper = TimeResampler(
                 freq=freq, closed=closed, label=label, origin=origin, offset=offset
             )

xarray/core/dataarray.py

@@ -110,6 +110,7 @@
         QueryEngineOptions,
         QueryParserOptions,
         ReindexMethodOptions,
+        ResampleCompatible,
         Self,
         SideOptions,
         T_ChunkDimFreq,
@@ -7244,19 +7245,15 @@ def coarsen(
     @_deprecate_positional_args("v2024.07.0")
     def resample(
         self,
-        indexer: Mapping[Hashable, str | Resampler] | None = None,
+        indexer: Mapping[Hashable, ResampleCompatible | Resampler] | None = None,
         *,
         skipna: bool | None = None,
         closed: SideOptions | None = None,
         label: SideOptions | None = None,
         offset: pd.Timedelta | datetime.timedelta | str | None = None,
         origin: str | DatetimeLike = "start_day",
         restore_coord_dims: bool | None = None,
-        **indexer_kwargs: str
-        | datetime.timedelta
-        | pd.Timedelta
-        | pd.DateOffset
-        | Resampler,
+        **indexer_kwargs: ResampleCompatible | Resampler,
     ) -> DataArrayResample:
         """Returns a Resample object for performing resampling operations.
 
@@ -7267,7 +7264,7 @@ def resample(
 
         Parameters
         ----------
-        indexer : Mapping of Hashable to str, optional
+        indexer : Mapping of Hashable to str, datetime.timedelta, pd.Timedelta, pd.DateOffset, or Resampler, optional
             Mapping from the dimension name to resample frequency [1]_. The
             dimension must be datetime-like.
         skipna : bool, optional
@@ -7291,7 +7288,7 @@ def resample(
         restore_coord_dims : bool, optional
             If True, also restore the dimension order of multi-dimensional
             coordinates.
-        **indexer_kwargs : str
+        **indexer_kwargs : str, datetime.timedelta, pd.Timedelta, pd.DateOffset, or Resampler
             The keyword arguments form of ``indexer``.
             One of indexer or indexer_kwargs must be provided.
 

xarray/core/dataset.py

@@ -162,6 +162,7 @@
         QueryEngineOptions,
         QueryParserOptions,
         ReindexMethodOptions,
+        ResampleCompatible,
         SideOptions,
         T_ChunkDimFreq,
         T_DatasetPadConstantValues,
@@ -10685,19 +10686,15 @@ def coarsen(
     @_deprecate_positional_args("v2024.07.0")
     def resample(
         self,
-        indexer: Mapping[Any, str | Resampler] | None = None,
+        indexer: Mapping[Any, ResampleCompatible | Resampler] | None = None,
         *,
         skipna: bool | None = None,
         closed: SideOptions | None = None,
         label: SideOptions | None = None,
         offset: pd.Timedelta | datetime.timedelta | str | None = None,
         origin: str | DatetimeLike = "start_day",
         restore_coord_dims: bool | None = None,
-        **indexer_kwargs: str
-        | datetime.timedelta
-        | pd.Timedelta
-        | pd.DateOffset
-        | Resampler,
+        **indexer_kwargs: ResampleCompatible | Resampler,
     ) -> DatasetResample:
         """Returns a Resample object for performing resampling operations.
 
@@ -10708,7 +10705,7 @@ def resample(
 
         Parameters
         ----------
-        indexer : Mapping of Hashable to str, optional
+        indexer : Mapping of Hashable to str, datetime.timedelta, pd.Timedelta, pd.DateOffset, or Resampler, optional
             Mapping from the dimension name to resample frequency [1]_. The
             dimension must be datetime-like.
         skipna : bool, optional
@@ -10732,7 +10729,7 @@ def resample(
         restore_coord_dims : bool, optional
             If True, also restore the dimension order of multi-dimensional
             coordinates.
-        **indexer_kwargs : str
+        **indexer_kwargs : str, datetime.timedelta, pd.Timedelta, pd.DateOffset, or Resampler
             The keyword arguments form of ``indexer``.
             One of indexer or indexer_kwargs must be provided.
 

xarray/core/resample_cftime.py

@@ -58,7 +58,7 @@
 from xarray.core.types import SideOptions
 
 if typing.TYPE_CHECKING:
-    from xarray.core.types import CFTimeDatetime
+    from xarray.core.types import CFTimeDatetime, ResampleCompatible
 
 
 class CFTimeGrouper:
@@ -75,11 +75,7 @@ class CFTimeGrouper:
 
     def __init__(
         self,
-        freq: str
-        | datetime.timedelta
-        | pd.Timedelta
-        | pd.DateOffset
-        | BaseCFTimeOffset,
+        freq: ResampleCompatible | BaseCFTimeOffset,
         closed: SideOptions | None = None,
         label: SideOptions | None = None,
         origin: str | CFTimeDatetime = "start_day",

xarray/core/types.py

@@ -309,3 +309,5 @@ def copy(
 Bins = Union[
     int, Sequence[int], Sequence[float], Sequence[pd.Timestamp], np.ndarray, pd.Index
 ]
+
+ResampleCompatible = Union[str, datetime.timedelta, pd.Timedelta, pd.DateOffset]

xarray/groupers.py

@@ -21,7 +21,13 @@
 from xarray.core.groupby import T_Group, _DummyGroup
 from xarray.core.indexes import safe_cast_to_index
 from xarray.core.resample_cftime import CFTimeGrouper
-from xarray.core.types import Bins, DatetimeLike, GroupIndices, SideOptions
+from xarray.core.types import (
+    Bins,
+    DatetimeLike,
+    GroupIndices,
+    ResampleCompatible,
+    SideOptions,
+)
 from xarray.core.variable import Variable
 
 __all__ = [
@@ -336,7 +342,7 @@ class TimeResampler(Resampler):
 
     Attributes
     ----------
-    freq : str, datetime.timedelta, pandas.Timestamp, pandas.DateOffset
+    freq : str, datetime.timedelta, pandas.Timestamp, or pandas.DateOffset
         Frequency to resample to. See `Pandas frequency
         aliases <https://pandas.pydata.org/pandas-docs/stable/user_guide/timeseries.html#offset-aliases>`_
         for a list of possible values.
@@ -358,7 +364,7 @@ class TimeResampler(Resampler):
         An offset timedelta added to the origin.
     """
 
-    freq: str | datetime.timedelta | pd.Timedelta | pd.DateOffset
+    freq: ResampleCompatible
     closed: SideOptions | None = field(default=None)
     label: SideOptions | None = field(default=None)
     origin: str | DatetimeLike = field(default="start_day")