Support rechunking to seasonal frequency with SeasonalResampler #10519

dhruvak001 · 2025-07-09T18:35:33Z

Closes Support rechunking to seasonal frequency with SeasonalResampler #10425
Tests added
User visible changes (including notable bug fixes) are documented in whats-new.rst
New functions/methods are listed in api.rst

users could not use SeasonResampler for chunking operations in xarray, despite it being a natural fit for seasonal data analysis. When attempting ds.chunk(time=SeasonResampler(["DJF", "MAMJ", "JAS", "ON"])), users encountered obscure errors because the chunking logic was hardcoded to only work with TimeResampler objects. This limitation prevented efficient seasonal analysis workflows and forced users to use workarounds or manual chunking strategies.

Now Added a generalized chunking approach by adding a resolve_chunks method to the Resampler base class and updating the chunking logic to work with all Resampler objects, not just TimeResampler. We also added a _for_chunking method to SeasonResampler that ensures drop_incomplete=False during chunking operations to prevent silent data loss. The solution maintains full backward compatibility with existing TimeResampler functionality while enabling seamless seasonal chunking

xarray/core/types.py

xarray/groupers.py

doc/whats-new.rst

xarray/groupers.py

xarray/tests/test_dataset.py

xarray/groupers.py

xarray/tests/test_dataset.py

xarray/core/dataset.py

xarray/tests/test_dataset.py

for more information, see https://pre-commit.ci

xarray/tests/test_dataset.py

dcherian · 2025-07-21T19:12:08Z

Almost there! I have a couple of small requests.

@keewis does this API look like it can work with the DGGSResampler idea we talked about? You should be able to rechunk to a "zoom level" so that a chunk completely contains an integer number of "parent cells".

* main: (46 commits) use the new syntax of ignoring bots (pydata#10668) modification methods on `Coordinates` (pydata#10318) Silence warnings from test_tutorial.py (pydata#10661) test: update write_empty test for zarr 3.1.2 (pydata#10665) Bump actions/checkout from 4 to 5 in the actions group (pydata#10652) Add load_datatree function (pydata#10649) Support compute=False from DataTree.to_netcdf (pydata#10625) Fix typos (pydata#10655) In case of misconfiguration of dataset.encoding `unlimited_dims` warn instead of raise (pydata#10648) fix ``auto_complex`` for ``open_datatree`` (pydata#10632) Fix bug indexing with boolean scalars (pydata#10635) Improve DataTree typing (pydata#10644) Update Cartopy and Iris references (pydata#10645) Empty release notes (pydata#10642) release notes for v2025.08.0 (pydata#10641) Fix `ds.merge` to prevent altering original object depending on join value (pydata#10596) Add asynchronous load method (pydata#10327) Add DataTree.prune() method … (pydata#10598) Avoid refining parent dimensions in NetCDF files (pydata#10623) clarify lazy behaviour and eager loading chunks=None in open_*-functions (pydata#10627) ...

xarray/core/dataset.py

Support chunking

0f10d91

github-actions bot added the topic-documentation label Jul 9, 2025

dhruvak001 changed the title ~~Support chunking~~ Support rechunking to seasonal frequency with SeasonalResampler Jul 9, 2025

DHRUVA KUMAR KAUSHAL added 2 commits July 10, 2025 00:06

whats new

3d4b62e

error resolving

527c48c

github-actions bot added the topic-typing label Jul 9, 2025

dcherian removed the topic-documentation label Jul 11, 2025

Merge branch 'main' into issue#10425

138e747

github-actions bot added the topic-documentation label Jul 12, 2025