Add to api.rst, fix whats-new.rst typo, raise error instead of warning

doc/api.rst

@@ -460,6 +460,7 @@ Dataset methods
    :toctree: generated/
 
    open_dataset
+   load_dataset
    open_mfdataset
    open_rasterio
    open_zarr
@@ -487,6 +488,7 @@ DataArray methods
    :toctree: generated/
 
    open_dataarray
+   load_dataarray
    DataArray.to_dataset
    DataArray.to_netcdf
    DataArray.to_pandas

doc/whats-new.rst

@@ -30,9 +30,9 @@ Enhancements
 - Clean up Python 2 compatibility in code (:issue:`2950`)
   By `Guido Imperiale <https://github.com/crusaderky>`_.
 - Implement ``load_dataset()`` and ``load_dataarray()`` as alternatives to ``open_dataset()`` and
-``open_dataarray()` to open, load into memory,
+``open_dataarray()`` to open, load into memory,
   and close files, returning the Dataset or DataArray. These functions are helpful
-  for avoiding file-lock errors when trying to write to files opened using ``open_dataset()`` or 
+  for avoiding file-lock errors when trying to write to files opened using ``open_dataset()`` or
   ``open_dataarray()``. (:issue:`2887`)
   By `Dan Nowacki <https://github.com/dnowacki-usgs>`_.
 

xarray/backends/api.py

@@ -205,9 +205,7 @@ def load_dataset(filename_or_obj, **kwargs):
     open_dataset
     """
     if 'cache' in kwargs:
-        warnings.warn(
-            'The cache argument has no effect in this context.',
-            SerializationWarning, stacklevel=2)
+        raise TypeError('cache has no effect in this context')
 
     with open_dataset(filename_or_obj, **kwargs) as ds:
         return ds.load()
@@ -233,9 +231,7 @@ def load_dataarray(filename_or_obj, **kwargs):
     open_dataarray
     """
     if 'cache' in kwargs:
-        warnings.warn(
-            'The cache argument has no effect in this context.',
-            SerializationWarning, stacklevel=2)
+        raise TypeError('cache has no effect in this context')
 
     with open_dataarray(filename_or_obj, **kwargs) as da:
         return da.load()