make more args kw only (except 'dim') (#6403)

* make more args kw only (except 'dim')

* add deprecation

* add forgotten deprecations

* doctest fixes

* fix some warnings

* remove expand_dims again

* undo expand_dims, fix mypy

* whats-new entry [skip-ci]

* add typing to _deprecate_positional_args helper

* Update xarray/util/deprecation_helpers.py

Co-authored-by: Michael Niklas  <mick.niklas@gmail.com>

* fix kw only for overload

* move typing

* restore # type: ignore

* add type ignores to test_deprecation_helpers

---------

Co-authored-by: Michael Niklas <mick.niklas@gmail.com>
Co-authored-by: Deepak Cherian <dcherian@users.noreply.github.com>

doc/whats-new.rst

@@ -30,6 +30,8 @@ New Features
 Breaking changes
 ~~~~~~~~~~~~~~~~
 
+- Made more arguments keyword-only (e.g. ``keep_attrs``, ``skipna``) for many :py:class:`xarray.DataArray` and
+  :py:class:`xarray.Dataset` methods (:pull:`6403`). By `Mathias Hauser <https://github.com/mathause>`_.
 - :py:meth:`Dataset.to_zarr` & :py:meth:`DataArray.to_zarr` require keyword
   arguments after the initial 7 positional arguments.
   By `Maximilian Roos <https://github.com/max-sixty>`_.

xarray/core/dataarray.py

@@ -66,6 +66,7 @@
 )
 from xarray.plot.accessor import DataArrayPlotAccessor
 from xarray.plot.utils import _get_units_from_attrs
+from xarray.util.deprecation_helpers import _deprecate_positional_args
 
 if TYPE_CHECKING:
     from typing import TypeVar, Union
@@ -954,6 +955,7 @@ def coords(self) -> DataArrayCoordinates:
     def reset_coords(
         self,
         names: Dims = None,
+        *,
         drop: Literal[False] = False,
     ) -> Dataset:
         ...
@@ -967,9 +969,11 @@ def reset_coords(
     ) -> Self:
         ...
 
+    @_deprecate_positional_args("v2023.10.0")
     def reset_coords(
         self,
         names: Dims = None,
+        *,
         drop: bool = False,
     ) -> Self | Dataset:
         """Given names of coordinates, reset them to become variables.
@@ -1287,9 +1291,11 @@ def chunksizes(self) -> Mapping[Any, tuple[int, ...]]:
         all_variables = [self.variable] + [c.variable for c in self.coords.values()]
         return get_chunksizes(all_variables)
 
+    @_deprecate_positional_args("v2023.10.0")
     def chunk(
         self,
         chunks: T_Chunks = {},  # {} even though it's technically unsafe, is being used intentionally here (#4667)
+        *,
         name_prefix: str = "xarray-",
         token: str | None = None,
         lock: bool = False,
@@ -1724,9 +1730,11 @@ def thin(
         ds = self._to_temp_dataset().thin(indexers, **indexers_kwargs)
         return self._from_temp_dataset(ds)
 
+    @_deprecate_positional_args("v2023.10.0")
     def broadcast_like(
         self,
         other: T_DataArrayOrSet,
+        *,
         exclude: Iterable[Hashable] | None = None,
     ) -> Self:
         """Broadcast this DataArray against another Dataset or DataArray.
@@ -1835,9 +1843,11 @@ def _reindex_callback(
 
         return da
 
+    @_deprecate_positional_args("v2023.10.0")
     def reindex_like(
         self,
         other: T_DataArrayOrSet,
+        *,
         method: ReindexMethodOptions = None,
         tolerance: int | float | Iterable[int | float] | None = None,
         copy: bool = True,
@@ -2005,9 +2015,11 @@ def reindex_like(
             fill_value=fill_value,
         )
 
+    @_deprecate_positional_args("v2023.10.0")
     def reindex(
         self,
         indexers: Mapping[Any, Any] | None = None,
+        *,
         method: ReindexMethodOptions = None,
         tolerance: float | Iterable[float] | None = None,
         copy: bool = True,
@@ -2787,9 +2799,11 @@ def stack(
         )
         return self._from_temp_dataset(ds)
 
+    @_deprecate_positional_args("v2023.10.0")
     def unstack(
         self,
         dim: Dims = None,
+        *,
         fill_value: Any = dtypes.NA,
         sparse: bool = False,
     ) -> Self:
@@ -2847,7 +2861,7 @@ def unstack(
         --------
         DataArray.stack
         """
-        ds = self._to_temp_dataset().unstack(dim, fill_value, sparse)
+        ds = self._to_temp_dataset().unstack(dim, fill_value=fill_value, sparse=sparse)
         return self._from_temp_dataset(ds)
 
     def to_unstacked_dataset(self, dim: Hashable, level: int | Hashable = 0) -> Dataset:
@@ -3198,9 +3212,11 @@ def drop_isel(
         dataset = dataset.drop_isel(indexers=indexers, **indexers_kwargs)
         return self._from_temp_dataset(dataset)
 
+    @_deprecate_positional_args("v2023.10.0")
     def dropna(
         self,
         dim: Hashable,
+        *,
         how: Literal["any", "all"] = "any",
         thresh: int | None = None,
     ) -> Self:
@@ -4696,10 +4712,12 @@ def _title_for_slice(self, truncate: int = 50) -> str:
 
         return title
 
+    @_deprecate_positional_args("v2023.10.0")
     def diff(
         self,
         dim: Hashable,
         n: int = 1,
+        *,
         label: Literal["upper", "lower"] = "upper",
     ) -> Self:
         """Calculate the n-th order discrete difference along given axis.
@@ -4985,10 +5003,12 @@ def sortby(
         ds = self._to_temp_dataset().sortby(variables, ascending=ascending)
         return self._from_temp_dataset(ds)
 
+    @_deprecate_positional_args("v2023.10.0")
     def quantile(
         self,
         q: ArrayLike,
         dim: Dims = None,
+        *,
         method: QuantileMethods = "linear",
         keep_attrs: bool | None = None,
         skipna: bool | None = None,
@@ -5103,9 +5123,11 @@ def quantile(
         )
         return self._from_temp_dataset(ds)
 
+    @_deprecate_positional_args("v2023.10.0")
     def rank(
         self,
         dim: Hashable,
+        *,
         pct: bool = False,
         keep_attrs: bool | None = None,
     ) -> Self:
@@ -5678,9 +5700,11 @@ def pad(
         )
         return self._from_temp_dataset(ds)
 
+    @_deprecate_positional_args("v2023.10.0")
     def idxmin(
         self,
         dim: Hashable | None = None,
+        *,
         skipna: bool | None = None,
         fill_value: Any = dtypes.NA,
         keep_attrs: bool | None = None,
@@ -5774,9 +5798,11 @@ def idxmin(
             keep_attrs=keep_attrs,
         )
 
+    @_deprecate_positional_args("v2023.10.0")
     def idxmax(
         self,
         dim: Hashable = None,
+        *,
         skipna: bool | None = None,
         fill_value: Any = dtypes.NA,
         keep_attrs: bool | None = None,
@@ -5870,9 +5896,11 @@ def idxmax(
             keep_attrs=keep_attrs,
         )
 
+    @_deprecate_positional_args("v2023.10.0")
     def argmin(
         self,
         dim: Dims = None,
+        *,
         axis: int | None = None,
         keep_attrs: bool | None = None,
         skipna: bool | None = None,
@@ -5970,9 +5998,11 @@ def argmin(
         else:
             return self._replace_maybe_drop_dims(result)
 
+    @_deprecate_positional_args("v2023.10.0")
     def argmax(
         self,
         dim: Dims = None,
+        *,
         axis: int | None = None,
         keep_attrs: bool | None = None,
         skipna: bool | None = None,
@@ -6317,9 +6347,11 @@ def curvefit(
             kwargs=kwargs,
         )
 
+    @_deprecate_positional_args("v2023.10.0")
     def drop_duplicates(
         self,
         dim: Hashable | Iterable[Hashable],
+        *,
         keep: Literal["first", "last", False] = "first",
     ) -> Self:
         """Returns a new DataArray with duplicate dimension values removed.

xarray/core/dataset.py

@@ -123,6 +123,7 @@
     calculate_dimensions,
 )
 from xarray.plot.accessor import DatasetPlotAccessor
+from xarray.util.deprecation_helpers import _deprecate_positional_args
 
 if TYPE_CHECKING:
     from numpy.typing import ArrayLike
@@ -4775,9 +4776,11 @@ def set_index(
             variables, coord_names=coord_names, indexes=indexes_
         )
 
+    @_deprecate_positional_args("v2023.10.0")
     def reset_index(
         self,
         dims_or_levels: Hashable | Sequence[Hashable],
+        *,
         drop: bool = False,
     ) -> Self:
         """Reset the specified index(es) or multi-index level(s).
@@ -5412,9 +5415,11 @@ def _unstack_full_reindex(
             variables, coord_names=coord_names, indexes=indexes
         )
 
+    @_deprecate_positional_args("v2023.10.0")
     def unstack(
         self,
         dim: Dims = None,
+        *,
         fill_value: Any = xrdtypes.NA,
         sparse: bool = False,
     ) -> Self:
@@ -6155,9 +6160,11 @@ def transpose(
             ds._variables[name] = var.transpose(*var_dims)
         return ds
 
+    @_deprecate_positional_args("v2023.10.0")
     def dropna(
         self,
         dim: Hashable,
+        *,
         how: Literal["any", "all"] = "any",
         thresh: int | None = None,
         subset: Iterable[Hashable] | None = None,
@@ -7583,10 +7590,12 @@ def _copy_attrs_from(self, other):
             if v in self.variables:
                 self.variables[v].attrs = other.variables[v].attrs
 
+    @_deprecate_positional_args("v2023.10.0")
     def diff(
         self,
         dim: Hashable,
         n: int = 1,
+        *,
         label: Literal["upper", "lower"] = "upper",
     ) -> Self:
         """Calculate the n-th order discrete difference along given axis.
@@ -7913,10 +7922,12 @@ def sortby(
             indices[key] = order if ascending else order[::-1]
         return aligned_self.isel(indices)
 
+    @_deprecate_positional_args("v2023.10.0")
     def quantile(
         self,
         q: ArrayLike,
         dim: Dims = None,
+        *,
         method: QuantileMethods = "linear",
         numeric_only: bool = False,
         keep_attrs: bool | None = None,
@@ -8091,9 +8102,11 @@ def quantile(
         )
         return new.assign_coords(quantile=q)
 
+    @_deprecate_positional_args("v2023.10.0")
     def rank(
         self,
         dim: Hashable,
+        *,
         pct: bool = False,
         keep_attrs: bool | None = None,
     ) -> Self:
@@ -9037,9 +9050,11 @@ def pad(
         attrs = self._attrs if keep_attrs else None
         return self._replace_with_new_dims(variables, indexes=indexes, attrs=attrs)
 
+    @_deprecate_positional_args("v2023.10.0")
     def idxmin(
         self,
         dim: Hashable | None = None,
+        *,
         skipna: bool | None = None,
         fill_value: Any = xrdtypes.NA,
         keep_attrs: bool | None = None,
@@ -9134,9 +9149,11 @@ def idxmin(
             )
         )
 
+    @_deprecate_positional_args("v2023.10.0")
     def idxmax(
         self,
         dim: Hashable | None = None,
+        *,
         skipna: bool | None = None,
         fill_value: Any = xrdtypes.NA,
         keep_attrs: bool | None = None,
@@ -9757,9 +9774,11 @@ def _wrapper(Y, *args, **kwargs):
 
         return result
 
+    @_deprecate_positional_args("v2023.10.0")
     def drop_duplicates(
         self,
         dim: Hashable | Iterable[Hashable],
+        *,
         keep: Literal["first", "last", False] = "first",
     ) -> Self:
         """Returns a new Dataset with duplicate dimension values removed.

xarray/core/groupby.py

@@ -43,6 +43,7 @@
     peek_at,
 )
 from xarray.core.variable import IndexVariable, Variable
+from xarray.util.deprecation_helpers import _deprecate_positional_args
 
 if TYPE_CHECKING:
     from numpy.typing import ArrayLike
@@ -1092,10 +1093,12 @@ def fillna(self, value: Any) -> T_Xarray:
         """
         return ops.fillna(self, value)
 
+    @_deprecate_positional_args("v2023.10.0")
     def quantile(
         self,
         q: ArrayLike,
         dim: Dims = None,
+        *,
         method: QuantileMethods = "linear",
         keep_attrs: bool | None = None,
         skipna: bool | None = None,