v0.19.0

scmdata v0.19.0 (2026-06-01)

Features

• Added {func}scmdata.groupby.RunGroupby.apply_parallel to perform parallelise large groupby operations (#262)

Bug Fixes

• Restored compatibility with pandas 3.0 and xarray 2025+ by patching four places where the older APIs are no longer accepted:

  • RunGroupBy.__init__ previously called numpy.issubdtype(col.dtype, numpy.number) to detect numeric meta columns, which raises TypeError on pandas.StringDtype (the new default for inferred string columns). Routed through pandas.api.types.is_numeric_dtype.
  • _xarray._many_to_one ended with Series[0] positional indexing, which pandas 3 has removed. Replaced with .iloc[0].
  • ScmRun.convert_unit, _binary_op and _unary_op wrote results via self._df.values[:] = .... pandas 3 makes DataFrame.values return a read-only array, so the in-place write raises ValueError. Switched to self._df.iloc[:, :] = ...; the binary/unary op sites additionally cast their right-hand side to float so that comparison ops (lt, eq, ne, ...) which return bool arrays continue to land as float64 in the underlying numeric block, preserving the prior silent-cast behaviour.
  • _read_nc passed use_cftime=True to xarray.load_dataset, which xarray 2025+ deprecates in favour of decode_times=xr.coders.CFDatetimeCoder(use_cftime=True). The deprecation otherwise fires a FutureWarning on every ScmRun.from_nc() call. Routes through the new API where available and falls back to the bare kwarg on xarray older than 2024.09.

  The previously-failing ScmRun.groupby, ScmRun.to_xarray, ScmRun.convert_unit, ScmRun.to_nc / ScmRun.from_nc, and the arithmetic and comparison operators on ScmRun now all run on both pandas 2 and pandas 3.

  (#321)

v0.18.0

Announcements

• Fixed incompatibility with the latest xarray version(s)

Changes

• Change 1
• edf9b62 bump: version 0.17.0 -> 0.18.0
• 3a89ec1 Fix test
• fd9cdef Try to fix more tests
• 14aac79 Add poetry export plugin to project deps
• 6dff117 Fix typo
• 8c7505c CHANGELOG
• b38434a Fix up tests
• f212616 Fix xarray pin

v0.17.0

Announcements

• We have fixed up our API to handle deprecated APIs in pandas and seaborn, you should no longer receive a million deprecation warnings when using scmdata 🎉

Changes

• Change 1
• 112f969 bump: version 0.16.1 -> 0.17.0
• ea5bcb5 Apply seaborn pin
• 8643ec3 Fix yet another deprecation warning
• fd48c82 More info on failure
• b546fb8 Add missing comment
• 7798045 Fix up tests
• 55836b5 CHANGELOG
• b22baa5 Remove seaborn misuse too
• dfbc9fb Workaround new pandas behaviour
• 3b61470 chore: Update pre-commit version
• 7c72a4e chore: Update precommit hook version
• b1ff87b chore(deps-dev): update ruff requirement from 0.1.1 to 0.1.6
• fb79b7c chore(deps-dev): update black requirement from 23.9.1 to 23.11.0
• 4163759 chore: Remove unused import
• 8381349 chore(deps-dev): update ruff requirement from 0.0.288 to 0.1.1

v0.16.1

Announcements

Hot fix release to fix an error in the CI that occurred when releasing v0.16.0. Announcements are unchanged and repeated below.

Breaking Changes

• Dropped support for Python 3.8 and relaxed requirements of pint and pyam-iamc

  This has led to a number of follow up issues:

  • documentation of our supported dependency versions (#277)
  • moving to NEP29 (#276)
  • a full review of dependencies (#278)
  • need to test against development versions of upstream repositories (#279)

  (#275)

Improvements

• Added support for {func}scmdata.run_append to append {class}pd.DataFrame objects

  This provides some performance benefits when performing large groupby operations in certain circumstances by
  reducing the number of required append operations. (#262)

Trivial/Internal Changes

• #267, #268

Changes

• Change 1
• 223355d bump: version 0.16.0 -> 0.16.1
• 657eab8 Attempt to fix up coverage statistics
• 8ea30a0 Shorten examples
• 016df89 Fix terminal width during doctests
• 042660e Fix up changelog tense
• 09d458e CHANGELOG
• 905cadf Update CI
• 919d65b Pass doctests

v0.16.0

Announcements

Breaking Changes

• Dropped support for Python 3.8 and relaxed requirements of pint and pyam-iamc

  This has led to a number of follow up issues:

  • documentation of our supported dependency versions (#277)
  • moving to NEP29 (#276)
  • a full review of dependencies (#278)
  • need to test against development versions of upstream repositories (#279)

  (#275)

Improvements

• Added support for {func}scmdata.run_append to append {class}pd.DataFrame objects

  This provides some performance benefits when performing large groupby operations in certain circumstances by
  reducing the number of required append operations. (#262)

Trivial/Internal Changes

• #267, #268

Changes

• ba65c09 bump: version 0.15.3 -> 0.16.0
• bf80b14 CHANGELOG
• e2c94d1 Update CI
• 1912b48 Drop Python 3.8
• 6153b2d Loosen off further
• 4fc8d4e Put Python 3.8 support back in
• d0ac3e7 Update requirements in pyproject.toml
• 302fac8 chore(deps-dev): update pandas-stubs requirement from <2 to <3
• 940c006 Update docstring
• 6d5d606 Fix up docs indentation
• 3306cd6 Apply suggestions from code review
• a3bede6 CHANGELOG
• 5071737 Update docs
• 82fe92c Refactor apply_parallel
• f984d8a Turn on Python 3.8 tests
• 69b3cbd Add future annotations to groupby
• bada923 docs: changelog
• da76fff Fix up leftover
• a40604b CHANGELOG
• cb27c6c Remove redundant line
• 5bd6eb3 chore: fix up coverage
• f7a176e chore: testing
• d1f0564 chore: Type adjustments
• eca06f7 chore: Missing ""
• 08a00b7 chore: Apply more type hints
• 0cc9bb8 feat: Add apply_parallel function to RunGroupBy

v0.15.3

Announcements

• Pandas requirement has been updated to allow anything >=1.1

Changes

• 4f9c3ea bump: version 0.15.2 -> 0.15.3
• 4a63fb6 Add installation steps to bump
• 97c3f17 Fix CI
• 64a60c2 Fix tests
• 5533020 Update pandas requirement from <2,>=1.1 to >=1.1,<3
• 500aa22 chore: Allow mypy job to fail until resolved
• 099b2db chore: Add Mika to the author list
• 44a0c19 chore: Fix easy doctests
• 9982914 chore: Remove optional group from install
• 8143c64 chore: Fix tests
• 4ccdd59 chore: Fix docs
• 3c00053 chore: Fix ruff checks
• 279bdb1 chore: Cleanup readme
• 95544ea chore: Bumping versions for numpy and black
• bf08733 chore: Initial migration