Published October 8, 2026
| Version v3.4.1
Software
Open
zarr-developers/zarr-python: v3.4.1
Authors/Creators
- Alistair Miles
- Davis Bennett1
- jakirkham
- David Stansby2
- Dimitri Papadopoulos Orfanos3
- Joe Hamman4
- M Bussonnier5
- Josh Moore6
- Max Jones1
- Tom Augspurger
- Deepak Cherian4
- Norman Rzepka7
- Hannes Spitz
- Sanket Verma
- James Bourbeau8
- Andrew Fulton9
- Ryan Abernathey10
- Gregory Lee11
- Ilan Gold12
- Mads R. B. Kristensen11
- Ian Hunt-Isaak4
- Zain Patel13
- Saransh Chopra14
- Matthew Rocklin15
- Nathan Zimmerman
- AWA DESTINY AGHANGU
- Christine P. Chai
- Chuck Daniels1
- 1. @developmentseed
- 2. Cambridge University Hospitals
- 3. CEA
- 4. @earth-mover
- 5. @Quansight-Labs
- 6. @openmicroscopy @German-BioImaging @image-coop
- 7. @scalableminds
- 8. @NVIDIA
- 9. Quansight
- 10. Earthmover PBC
- 11. NVIDIA
- 12. Memorial Sloan Kettering Cancer Center
- 13. Maven Securities
- 14. EPFL / Logitech
- 15. @coiled
Description
<!-- Release notes generated using configuration in .github/release.yml at main -->
What's Changed
Dependency updates
- chore(deps): bump the python-dependencies group with 5 updates by @dependabot[bot] in https://github.com/zarr-developers/zarr-python/pull/4371
- chore(deps): bump the actions group across 1 directory with 4 updates by @dependabot[bot] in https://github.com/zarr-developers/zarr-python/pull/4370
- chore(deps-dev): bump the python-dependencies group with 4 updates by @dependabot[bot] in https://github.com/zarr-developers/zarr-python/pull/4394
- chore(deps): bump codecov/codecov-action from 7.0.0 to 7.1.1 in the actions group by @dependabot[bot] in https://github.com/zarr-developers/zarr-python/pull/4393
- chore(deps): bump astral-sh/setup-uv from 10.1.0 to 10.2.0 in the actions group by @dependabot[bot] in https://github.com/zarr-developers/zarr-python/pull/4460
- chore(deps): bump the python-dependencies group with 7 updates by @dependabot[bot] in https://github.com/zarr-developers/zarr-python/pull/4461
- chore(deps): bump the uv group across 2 directories with 2 updates by @dependabot[bot] in https://github.com/zarr-developers/zarr-python/pull/4463
- chore(deps): bump urllib3 from 2.7.0 to 2.8.0 by @dependabot[bot] in https://github.com/zarr-developers/zarr-python/pull/4462
What's Changed
- ci: keep subpackage pull requests out of generated zarr release notes by @d-v-b in https://github.com/zarr-developers/zarr-python/pull/4361
- fix: replace runtime assert statements with explicit checks by @d-v-b in https://github.com/zarr-developers/zarr-python/pull/4363
- fix(zarr-indexing): replace runtime assert statements with explicit checks by @d-v-b in https://github.com/zarr-developers/zarr-python/pull/4364
- fix(ci): preserve branch zarr in xarray downstream tests by @glaziermag in https://github.com/zarr-developers/zarr-python/pull/4368
- chore: centralize development and CI verbs in just by @d-v-b in https://github.com/zarr-developers/zarr-python/pull/4372
- fix: accept uint8 dtype aliases in Zarr v2 by @guhou-hvi in https://github.com/zarr-developers/zarr-python/pull/4381
- perf: cut the fill_value check on the chunk write path by @PursuitOfDataScience in https://github.com/zarr-developers/zarr-python/pull/4382
- fix(dtype): accept any byte order for byte-order-irrelevant v2 dtype names by @d-v-b in https://github.com/zarr-developers/zarr-python/pull/4385
- fix(ci): run zarr-indexing tests on the matrix interpreter by @d-v-b in https://github.com/zarr-developers/zarr-python/pull/4390
- refactor: keep the blocked all_equal scan on the CPU buffer by @d-v-b in https://github.com/zarr-developers/zarr-python/pull/4392
- chore: bump numcodecs min version by @Oisin-M in https://github.com/zarr-developers/zarr-python/pull/4396
- fix(sharding): reject variable-size codecs in index_codecs by @d-v-b in https://github.com/zarr-developers/zarr-python/pull/4397
- fix(dtype): fix nested v2 round trips and detect unsupported field conversions by @d-v-b in https://github.com/zarr-developers/zarr-python/pull/4340
- fix(dtype): resolve struct fields with the registry that resolves the struct by @d-v-b in https://github.com/zarr-developers/zarr-python/pull/4387
- fix(store): run every LocalStore filesystem call off the event loop by @d-v-b in https://github.com/zarr-developers/zarr-python/pull/4353
- fix(storage): yield only direct children from FsspecStore.list_dir by @d-v-b in https://github.com/zarr-developers/zarr-python/pull/4402
- fix(dtype): preserve scaled generic time units and normalize the μs alias by @d-v-b in https://github.com/zarr-developers/zarr-python/pull/4342
- docs: show package tag instead of monorepo release in subpackage docs by @maxrjones in https://github.com/zarr-developers/zarr-python/pull/4229
- chore: keep sub-package pyproject.toml standalone; overlay in-repo zarr from just by @d-v-b in https://github.com/zarr-developers/zarr-python/pull/4406
- test: deflake test_encode_and_write_as_completed_cancels_stray_writes_on_failure by @d-v-b in https://github.com/zarr-developers/zarr-python/pull/4409
- build: ground sub-package packaging in current uv/hatch/setuptools-scm guidance by @d-v-b in https://github.com/zarr-developers/zarr-python/pull/4407
- fix(array): reject unknown keys in ArrayConfig.from_dict by @d-v-b in https://github.com/zarr-developers/zarr-python/pull/4414
- fix(indexing): avoid full-grid allocations for sparse selections by @d-v-b in https://github.com/zarr-developers/zarr-python/pull/4356
- fix: byte-order bugs and little-endian test assumptions on big-endian hosts by @d-v-b in https://github.com/zarr-developers/zarr-python/pull/4435
- fix: honor storage_options in save and save_group by @Rodrigo-Palma in https://github.com/zarr-developers/zarr-python/pull/4415
- fix: list nested prefixes when FsspecStore path is "" or "/" by @bendichter in https://github.com/zarr-developers/zarr-python/pull/4452
- fix(tests): repair docstring-consistency test and align create_array docs by @guhou-hvi in https://github.com/zarr-developers/zarr-python/pull/4417
- fix(group): apply config when require_array returns an existing array by @d-v-b in https://github.com/zarr-developers/zarr-python/pull/4413
- fix: accept must_understand=false extra fields in v3 group metadata by @anishmehta24 in https://github.com/zarr-developers/zarr-python/pull/4391
- feat(api): declare mode and data on create by @d-v-b in https://github.com/zarr-developers/zarr-python/pull/4455
- fix(group): create group helper arrays in the group's zarr format by @d-v-b in https://github.com/zarr-developers/zarr-python/pull/4412
- fix(api): validate a new node before deleting the existing one by @d-v-b in https://github.com/zarr-developers/zarr-python/pull/4410
- fix(chunk-grids): require chunk sizes of at least 1 and read the 0, false and true sizes older releases stored by @d-v-b in https://github.com/zarr-developers/zarr-python/pull/4334
- test(chunk-grids): sample the full rectilinear chunk grid declaration space by @d-v-b in https://github.com/zarr-developers/zarr-python/pull/4377
- fix(chunk-grids): read mixed regular/rectilinear chunk grids written by zarr 3.2.x by @d-v-b in https://github.com/zarr-developers/zarr-python/pull/4375
- test(stateful): bound how far append grows an axis in the array lifecycle test by @d-v-b in https://github.com/zarr-developers/zarr-python/pull/4470
- fix(sharding): reject a stored shard too short to hold its index on every path by @d-v-b in https://github.com/zarr-developers/zarr-python/pull/4475
- fix(chunk-grids): judge every chunk specification by the chunk normalizer alone by @d-v-b in https://github.com/zarr-developers/zarr-python/pull/4376
- fix: avoid copying 0-d chunk data when indexing CPU NDBuffers by @janickm in https://github.com/zarr-developers/zarr-python/pull/4466
- fix(sharding): validate nested sharding codecs and reject an inner chunk size of 0 by @d-v-b in https://github.com/zarr-developers/zarr-python/pull/4480
- Fix/from array overwrite source by @ianhi in https://github.com/zarr-developers/zarr-python/pull/4405
- fix(ci): run xarray's backend tests from their new package by @d-v-b in https://github.com/zarr-developers/zarr-python/pull/4491
- docs: 3.4.1 release notes by @d-v-b in https://github.com/zarr-developers/zarr-python/pull/4489
New Contributors
- @guhou-hvi made their first contribution in https://github.com/zarr-developers/zarr-python/pull/4381
- @PursuitOfDataScience made their first contribution in https://github.com/zarr-developers/zarr-python/pull/4382
- @Oisin-M made their first contribution in https://github.com/zarr-developers/zarr-python/pull/4396
- @Rodrigo-Palma made their first contribution in https://github.com/zarr-developers/zarr-python/pull/4415
- @bendichter made their first contribution in https://github.com/zarr-developers/zarr-python/pull/4452
- @anishmehta24 made their first contribution in https://github.com/zarr-developers/zarr-python/pull/4391
Full Changelog: https://github.com/zarr-developers/zarr-python/compare/v3.4.0...v3.4.1
Files
zarr-developers/zarr-python-v3.4.1.zip
Additional details
Related works
- Is supplement to
- Software: https://github.com/zarr-developers/zarr-python/tree/v3.4.1 (URL)
Software
- Repository URL
- https://github.com/zarr-developers/zarr-python