release v2025.11.0

doc/whats-new.rst

@@ -6,9 +6,9 @@
 What's New
 ==========
 
-.. _whats-new.2025.10.2:
+.. _whats-new.2025.11.0:
 
-v2025.10.2 (unreleased)
+v2025.11.0 (unreleased)
 -----------------------
 
 New Features
@@ -17,109 +17,16 @@ New Features
 - :py:func:`merge` and :py:func:`concat` now support :py:class:`DataTree`
   objects (:issue:`9790`, :issue:`9778`).
   By `Stephan Hoyer <https://github.com/shoyer>`_.
-- The ``h5netcdf`` engine has support for pseudo ``NETCDF4_CLASSIC`` files, meaning variables and attributes are cast to supported types. Note that the saved files won't be recognized as genuine ``NETCDF4_CLASSIC`` files until ``h5netcdf`` adds support with version 1.7.0. (:issue:`10676`, :pull:`10686`).
+- The ``h5netcdf`` engine has support for pseudo ``NETCDF4_CLASSIC`` files, meaning variables and attributes are cast to supported types. Note that the saved files won't be recognized as genuine ``NETCDF4_CLASSIC`` files until ``h5netcdf`` adds support with version 1.7.0 (:issue:`10676`, :pull:`10686`).
   By `David Huard <https://github.com/huard>`_.
 - Support comparing :py:class:`DataTree` objects with :py:func:`testing.assert_allclose` (:pull:`10887`).
   By `Justus Magin <https://github.com/keewis>`_.
+- Add support for ``chunks="auto"`` for cftime datasets (:issue:`9834`, :pull:`10527`).
+  By `Charles Turner <https://github.com/charles-turner-1>`_.
 
 Breaking Changes
 ~~~~~~~~~~~~~~~~
-
-
-Deprecations
-~~~~~~~~~~~~
-
-
-Bug Fixes
-~~~~~~~~~
-- Fix h5netcdf backend for format=None, use same rule as netcdf4 backend (:pull:`10859`).
-  By `Kai Mühlbauer <https://github.com/kmuehlbauer>`_
-- ``netcdf4`` and ``pydap`` backends now use stricter URL detection to avoid incorrectly claiming
-  remote URLs. The ``pydap`` backend now only claims URLs with explicit DAP protocol indicators
-  (``dap2://`` or ``dap4://`` schemes, or ``/dap2/`` or ``/dap4/`` in the URL path). This prevents
-  both backends from claiming remote Zarr stores and other non-DAP URLs without an explicit
-  ``engine=`` argument. (:pull:`10804`). By `Ian Hunt-Isaak <https://github.com/ianhi>`_.
-- Fix indexing with empty arrays for scipy & h5netcdf backends which now resolves to empty slices (:issue:`10867`, :pull:`10870`).
-  By `Kai Mühlbauer <https://github.com/kmuehlbauer>`_
-- Fix error handling issue in ``decode_cf_variables`` when decoding fails - the exception is now re-raised
-  correctly, with a note added about the variable name that caused the error (:issue:`10873`, :pull:`10886`).
-  By `Jonas L. Bertelsen <https://github.com/jonaslb>`_
-
-Performance
-~~~~~~~~~~~
-
-- Speedup and reduce memory usage of :py:func:`concat`. Magnitude of improvement scales
-  with size of the concatenation dimension. By `Deepak Cherian <https://github.com/dcherian>`_.
-  :issue:`10864` :pull:`10866`.
-
-Documentation
-~~~~~~~~~~~~~
-
-
-Internal Changes
-~~~~~~~~~~~~~~~~
-
-.. _whats-new.2025.10.1:
-
-v2025.10.1 (October 7, 2025)
-----------------------------
-
-This release reverts a breaking change to Xarray's preferred netCDF backend.
-
-Breaking changes
-~~~~~~~~~~~~~~~~
-
-- Xarray's default engine for reading/writing netCDF files has been reverted to
-  prefer netCDF4 over h5netcdf over scipy, which was the default before
-  v2025.09.1. This change had larger implications for the ecosystem than we
-  anticipated. We are still considering changing the default in the future, but
-  will be a bit more careful about the implications. See :issue:`10657` and
-  linked issues for discussion. The behavior can still be customized, e.g., with
-  ``xr.set_options(netcdf_engine_order=['h5netcdf', 'netcdf4', 'scipy'])``.
-  By `Stephan Hoyer <https://github.com/shoyer>`_.
-
-New features
-~~~~~~~~~~~~
-
-- Coordinates are ordered to match dims when displaying Xarray objects. (:pull:`10778`).
-  By `Julia Signell <https://github.com/jsignell>`_.
-
-Bug fixes
-~~~~~~~~~
-- Fix error raised when writing scalar variables to Zarr with ``region={}``
-  (:pull:`10796`).
-  By `Stephan Hoyer <https://github.com/shoyer>`_.
-
-
-
-.. _whats-new.2025.09.1:
-
-v2025.09.1 (September 29, 2025)
--------------------------------
-
-This release contains improvements to netCDF IO and the
-:py:func:`DataTree.from_dict` constructor, as well as a variety of bug fixes.
-In particular, the default netCDF backend has switched from netCDF4 to h5netcdf,
-which is typically faster.
-
-Thanks to the 17 contributors to this release:
-Claude, Deepak Cherian, Dimitri Papadopoulos Orfanos, Dylan H. Morris, Emmanuel Mathot, Ian Hunt-Isaak, Joren Hammudoglu, Julia Signell, Justus Magin, Maximilian Roos, Nick Hodgskin, Spencer Clark, Stephan Hoyer, Tom Nicholas, gronniger, joseph nowak and pierre-manchon
-
-New Features
-~~~~~~~~~~~~
-
-- :py:func:`DataTree.from_dict` now supports passing in ``DataArray`` and nested
-  dictionary values, and has a ``coords`` argument for specifying coordinates as
-  ``DataArray`` objects (:pull:`10658`).
-- ``engine='netcdf4'`` now supports reading and writing in-memory netCDF files.
-  All of Xarray's netCDF backends now support in-memory reads and writes
-  (:pull:`10624`).
-  By `Stephan Hoyer <https://github.com/shoyer>`_.
-
-Breaking changes
-~~~~~~~~~~~~~~~~
-
-- **All xarray operations now preserve attributes by default** (:issue:`3891`, :issue:`2582`).
+- All xarray operations now preserve attributes by default (:issue:`3891`, :issue:`2582`).
   Previously, operations would drop attributes unless explicitly told to preserve them via ``keep_attrs=True``.
   Additionally, when attributes are preserved in binary operations, they now combine attributes from both
   operands using ``drop_conflicts`` (keeping matching attributes, dropping conflicts), instead of keeping
@@ -129,7 +36,7 @@ Breaking changes
 
   .. code-block:: python
 
-      # Before (xarray <2025.09.1):
+      # Before (xarray <2025.11.0):
       data = xr.DataArray([1, 2, 3], attrs={"units": "meters", "long_name": "height"})
       result = data.mean()
       result.attrs  # {}  - Attributes lost!
@@ -205,6 +112,98 @@ Breaking changes
 
   By `Maximilian Roos <https://github.com/max-sixty>`_.
 
+
+Bug Fixes
+~~~~~~~~~
+- Fix h5netcdf backend for format=None, use same rule as netcdf4 backend (:pull:`10859`).
+  By `Kai Mühlbauer <https://github.com/kmuehlbauer>`_.
+- ``netcdf4`` and ``pydap`` backends now use stricter URL detection to avoid incorrectly claiming
+  remote URLs. The ``pydap`` backend now only claims URLs with explicit DAP protocol indicators
+  (``dap2://`` or ``dap4://`` schemes, or ``/dap2/`` or ``/dap4/`` in the URL path). This prevents
+  both backends from claiming remote Zarr stores and other non-DAP URLs without an explicit
+  ``engine=`` argument (:pull:`10804`).
+  By `Ian Hunt-Isaak <https://github.com/ianhi>`_.
+- Fix indexing with empty arrays for scipy & h5netcdf backends which now resolves to empty slices (:issue:`10867`, :pull:`10870`).
+  By `Kai Mühlbauer <https://github.com/kmuehlbauer>`_
+- Fix error handling issue in ``decode_cf_variables`` when decoding fails - the exception is now re-raised
+  correctly, with a note added about the variable name that caused the error (:issue:`10873`, :pull:`10886`).
+  By `Jonas L. Bertelsen <https://github.com/jonaslb>`_.
+- Fix ``equivalent`` for numpy scalar nan comparison (:issue:`10833`, :pull:`10838`).
+  By `Maximilian Roos <https://github.com/max-sixty>`_.
+- Support non-``DataArray`` outputs in :py:meth:`Dataset.map` (:issue:`10835`, :pull:`10839`).
+  By `Maximilian Roos <https://github.com/max-sixty>`_.
+- Support ``drop_sel`` on ``MultiIndex`` objects (:issue:`10862`, :pull:`10863`).
+  By `Aled Owen <https://github.com/owena11>`_.
+
+Performance
+~~~~~~~~~~~
+
+- Speedup and reduce memory usage of :py:func:`concat`. Magnitude of improvement scales
+  with size of the concatenation dimension (:issue:`10864`, :pull:`10866`).
+  By `Deepak Cherian <https://github.com/dcherian>`_.
+
+Documentation
+~~~~~~~~~~~~~
+
+.. _whats-new.2025.10.1:
+
+v2025.10.1 (October 7, 2025)
+----------------------------
+
+This release reverts a breaking change to Xarray's preferred netCDF backend.
+
+Breaking changes
+~~~~~~~~~~~~~~~~
+
+- Xarray's default engine for reading/writing netCDF files has been reverted to
+  prefer netCDF4 over h5netcdf over scipy, which was the default before
+  v2025.09.1. This change had larger implications for the ecosystem than we
+  anticipated. We are still considering changing the default in the future, but
+  will be a bit more careful about the implications. See :issue:`10657` and
+  linked issues for discussion. The behavior can still be customized, e.g., with
+  ``xr.set_options(netcdf_engine_order=['h5netcdf', 'netcdf4', 'scipy'])``.
+  By `Stephan Hoyer <https://github.com/shoyer>`_.
+
+New features
+~~~~~~~~~~~~
+
+- Coordinates are ordered to match dims when displaying Xarray objects. (:pull:`10778`).
+  By `Julia Signell <https://github.com/jsignell>`_.
+
+Bug fixes
+~~~~~~~~~
+- Fix error raised when writing scalar variables to Zarr with ``region={}``
+  (:pull:`10796`).
+  By `Stephan Hoyer <https://github.com/shoyer>`_.
+
+
+.. _whats-new.2025.09.1:
+
+v2025.09.1 (September 29, 2025)
+-------------------------------
+
+This release contains improvements to netCDF IO and the
+:py:func:`DataTree.from_dict` constructor, as well as a variety of bug fixes.
+In particular, the default netCDF backend has switched from netCDF4 to h5netcdf,
+which is typically faster.
+
+Thanks to the 17 contributors to this release:
+Claude, Deepak Cherian, Dimitri Papadopoulos Orfanos, Dylan H. Morris, Emmanuel Mathot, Ian Hunt-Isaak, Joren Hammudoglu, Julia Signell, Justus Magin, Maximilian Roos, Nick Hodgskin, Spencer Clark, Stephan Hoyer, Tom Nicholas, gronniger, joseph nowak and pierre-manchon
+
+New Features
+~~~~~~~~~~~~
+
+- :py:func:`DataTree.from_dict` now supports passing in ``DataArray`` and nested
+  dictionary values, and has a ``coords`` argument for specifying coordinates as
+  ``DataArray`` objects (:pull:`10658`).
+- ``engine='netcdf4'`` now supports reading and writing in-memory netCDF files.
+  All of Xarray's netCDF backends now support in-memory reads and writes
+  (:pull:`10624`).
+  By `Stephan Hoyer <https://github.com/shoyer>`_.
+
+Breaking changes
+~~~~~~~~~~~~~~~~
+
 - :py:meth:`Dataset.update` now returns ``None``, instead of the updated dataset. This
   completes the deprecation cycle started in version 0.17. The method still updates the
   dataset in-place. (:issue:`10167`)