Raise on inplace=True

doc/whats-new.rst

@@ -24,10 +24,13 @@ This release increases the minimum required Python version from 3.5.0 to 3.5.3
 Breaking changes
 ~~~~~~~~~~~~~~~~
 
-  The ``isel_points`` and ``sel_points`` methods are removed, having been deprecated
+- The ``isel_points`` and ``sel_points`` methods are removed, having been deprecated
   since v0.10.0. These are redundant with the ``isel`` / ``sel`` methods.
   See :ref:`vectorized_indexing` for the details 
   By `Maximilian Roos <https://github.com/max-sixty>`_ 
+- The ``inplace`` kwarg for public methods now raises an error, having been deprecated
+  since v0.11.0.
+  By `Maximilian Roos <https://github.com/max-sixty>`_ 
 
 New functions/methods
 ~~~~~~~~~~~~~~~~~~~~~

xarray/core/dataarray.py

@@ -700,30 +700,17 @@ def reset_coords(
         drop : bool, optional
             If True, remove coordinates instead of converting them into
             variables.
-        inplace : bool, optional
-            If True, modify this object in place. Otherwise, create a new
-            object.
 
         Returns
         -------
-        Dataset, or DataArray if ``drop == True``, or None if
-        ``inplace == True``
+        Dataset, or DataArray if ``drop == True``
         """
-        inplace = _check_inplace(inplace)
-        if inplace and not drop:
-            raise ValueError(
-                "cannot reset coordinates in-place on a "
-                "DataArray without ``drop == True``"
-            )
+        _check_inplace(inplace)
         if names is None:
             names = set(self.coords) - set(self.dims)
         dataset = self.coords.to_dataset().reset_coords(names, drop)
         if drop:
-            if inplace:
-                self._coords = dataset._variables
-                return None
-            else:
-                return self._replace(coords=dataset._variables)
+            return self._replace(coords=dataset._variables)
         else:
             if self.name is None:
                 raise ValueError(
@@ -1485,9 +1472,6 @@ def set_index(
         append : bool, optional
             If True, append the supplied index(es) to the existing index(es).
             Otherwise replace the existing index(es) (default).
-        inplace : bool, optional
-            If True, set new index(es) in-place. Otherwise, return a new
-            DataArray object.
         **indexes_kwargs: optional
             The keyword arguments form of ``indexes``.
             One of indexes or indexes_kwargs must be provided.
@@ -1496,7 +1480,6 @@ def set_index(
         -------
         obj : DataArray
             Another DataArray, with this data but replaced coordinates.
-            Return None if inplace=True.
 
         Example
         -------
@@ -1526,14 +1509,10 @@ def set_index(
         --------
         DataArray.reset_index
         """
-        inplace = _check_inplace(inplace)
+        _check_inplace(inplace)
         indexes = either_dict_or_kwargs(indexes, indexes_kwargs, "set_index")
         coords, _ = merge_indexes(indexes, self._coords, set(), append=append)
-        if inplace:
-            self._coords = coords
-            return None
-        else:
-            return self._replace(coords=coords)
+        return self._replace(coords=coords)
 
     def reset_index(
         self,
@@ -1551,36 +1530,29 @@ def reset_index(
         drop : bool, optional
             If True, remove the specified indexes and/or multi-index levels
             instead of extracting them as new coordinates (default: False).
-        inplace : bool, optional
-            If True, modify the dataarray in-place. Otherwise, return a new
-            DataArray object.
 
         Returns
         -------
         obj : DataArray
             Another dataarray, with this dataarray's data but replaced
-            coordinates. If ``inplace == True``, return None.
+            coordinates.
 
         See Also
         --------
         DataArray.set_index
         """
-        inplace = _check_inplace(inplace)
+        _check_inplace(inplace)
         coords, _ = split_indexes(
             dims_or_levels, self._coords, set(), self._level_coords, drop=drop
         )
-        if inplace:
-            self._coords = coords
-            return None
-        else:
-            return self._replace(coords=coords)
+        return self._replace(coords=coords)
 
     def reorder_levels(
         self,
         dim_order: Mapping[Hashable, Sequence[int]] = None,
         inplace: bool = None,
         **dim_order_kwargs: Sequence[int]
-    ) -> Optional["DataArray"]:
+    ) -> "DataArray":
         """Rearrange index levels using input order.
 
         Parameters
@@ -1589,9 +1561,6 @@ def reorder_levels(
             Mapping from names matching dimensions and values given
             by lists representing new level orders. Every given dimension
             must have a multi-index.
-        inplace : bool, optional
-            If True, modify the dataarray in-place. Otherwise, return a new
-            DataArray object.
         **dim_order_kwargs: optional
             The keyword arguments form of ``dim_order``.
             One of dim_order or dim_order_kwargs must be provided.
@@ -1600,9 +1569,9 @@ def reorder_levels(
         -------
         obj : DataArray
             Another dataarray, with this dataarray's data but replaced
-            coordinates. If ``inplace == True``, return None.
+            coordinates.
         """
-        inplace = _check_inplace(inplace)
+        _check_inplace(inplace)
         dim_order = either_dict_or_kwargs(dim_order, dim_order_kwargs, "reorder_levels")
         replace_coords = {}
         for dim, order in dim_order.items():
@@ -1613,11 +1582,7 @@ def reorder_levels(
             replace_coords[dim] = IndexVariable(coord.dims, index.reorder_levels(order))
         coords = self._coords.copy()
         coords.update(replace_coords)
-        if inplace:
-            self._coords = coords
-            return None
-        else:
-            return self._replace(coords=coords)
+        return self._replace(coords=coords)
 
     def stack(
         self,