Drop Python 3.9 support #2998

PPsyrius · 2025-10-09T06:18:48Z

Proposed change

Drops Python 3.9 support due to its impending EOL status as of October 2025 - I'm waiting for the final deprecation notice before marking this as ready.
Upgrades syntax to Python 3.10 standard (mainly PEP 604 and dropping importlib-metadata which is now built-in as importlib.metadata).
Remove zipp>=3.19.1 pinning in dev and test requirements (from what I understand, this was previously only used by importlib-metadata).

Type of change

New country/market holidays support (thank you!)
Supported country/market holidays update (calendar discrepancy fix, localization)
Existing code/documentation/test/process quality improvement (best practice, cleanup, refactoring, optimization)
Dependency update (version deprecation/pin/upgrade)
Bugfix (non-breaking change which fixes an issue)
Breaking change (a code change causing existing functionality to break)
New feature (new holidays functionality in general)

Checklist

I've read and followed the contributing guidelines.
I've run make check locally; all checks and tests passed.

https://peps.python.org/pep-0604/

coderabbitai · 2025-10-09T06:19:19Z

Summary by CodeRabbit

Chores
- Dropped Python 3.9 support; minimum required version is now 3.10.
- Updated tooling configs to target Python 3.10+.
Refactor
- Modernized type hints across the codebase to use PEP 604 unions (X | None), with no functional changes.
- Streamlined public API annotations for holiday utilities and exporters.
Tests
- Updated CI/tox targets to Python 3.10–3.14.
- Simplified test requirements (numpy constraints, removed legacy pins).
- Cleaned up metadata imports for tests.

Walkthrough

Dropped Python 3.9 support and modernized many type hints to PEP 604 union syntax (A | B) across CI, tooling, core, calendars, groups, countries, scripts, and tests. Adjusted pyproject/tox/CI matrices and cleaned up unused typing imports. No runtime logic changes reported.

Changes

Cohort / File(s)	Summary of changes
CI & tooling `\.github/workflows/ci-cd.yml`, `tox.ini`, `pyproject.toml`, `\.pre-commit-config.yaml`, `requirements/dev.txt`, `requirements/tests.txt`	Removed Python 3.9 from CI/tox matrices; bumped requires-python to >=3.10; updated ruff/pyupgrade targets to py310; consolidated test dependency pins; removed zipp pin.
Core framework & utils `holidays/holiday_base.py`, `holidays/observed_holiday_base.py`, `holidays/utils.py`, `holidays/registry.py`, `holidays/ical.py`, `holidays/mixins/child_entity.py`, `holidays/observed_holiday_base.py`	Replaced `Optional`/`Union` type hints with PEP 604 unions (`X
Calendars `holidays/calendars/*` (e.g., `balinese_saka.py`, `buddhist.py`, `burmese.py`, `chinese.py`, `hebrew.py`, `hindu.py`, `mandaean.py`, `mongolian.py`, `persian.py`, `sinhala.py`, `thai.py`, `tibetan.py`)	Converted return/tuple annotations from `Optional[...]`/`Union[...]` to `date
Groups `holidays/groups/*` (e.g., `balinese_saka.py`, `buddhist.py`, `burmese.py`, `chinese.py`, `eastern.py`, `hebrew.py`, `hindu.py`, `mandaean.py`, `mongolian.py`, `persian.py`, `sinhala.py`, `thai.py`, `tibetan.py`)	Migrated many internal helper and add* methods to PEP 604 unions for optional dates and union params (e.g., `int
Countries `holidays/countries/*` (e.g., `angola.py`, `guernsey.py`, `jersey.py`, `taiwan.py`, `united_kingdom.py`, `united_states.py`)	Updated field and method annotations to use `
Scripts & misc `scripts/archive_links.py`, `tests/test_package.py`	Updated script type hints from `Optional[...]` to `X

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related PRs

Switch to Python 3.14 #2997 — Overlaps CI/tooling and Python version changes (ci workflow, pyproject.toml).
Add Python 3.14 (beta) to CI/CD #2650 — Related CI/test-matrix and tooling updates (tox/env and test requirements).
Add Bhutan holidays #2635 — Touches calendar code (tibetan) that this PR also updated type annotations for.

Suggested reviewers

arkid15r
KJhellico

Pre-merge checks and finishing touches

✅ Passed checks (3 passed)

Check name	Status	Explanation
Title Check	✅ Passed	The title “Drop Python 3.9 support” directly reflects the pull request’s primary change of removing Python 3.9 compatibility and is both concise and specific, giving reviewers immediate clarity on the update.
Description Check	✅ Passed	The description clearly outlines the removal of Python 3.9 support, the switch to Python 3.10 PEP 604 union syntax, and the elimination of the zipp pin and importlib-metadata dependency, which directly matches the changes in the diff and provides relevant context for reviewers.
Docstring Coverage	✅ Passed	Docstring coverage is 81.25% which is sufficient. The required threshold is 80.00%.

✨ Finishing touches

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🧪 Generate unit tests (beta)

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Post copyable unit tests in a comment

📜 Recent review details

Configuration used: Path: .coderabbit.yaml

Review profile: ASSERTIVE

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 60d2a9c and cd48446.

📒 Files selected for processing (1)

holidays/holiday_base.py (14 hunks)

🧰 Additional context used

🧠 Learnings (1)

📚 Learning: 2025-04-08T14:46:10.656Z

Learnt from: KJhellico
PR: vacanza/holidays#2437
File: holidays/countries/bhutan.py:27-30
Timestamp: 2025-04-08T14:46:10.656Z
Learning: For country classes in the holidays library, there's no need to explicitly specify `supported_categories = (PUBLIC,)` when PUBLIC is the only category being used, as it's already the default category inherited from HolidayBase.

Applied to files:

holidays/holiday_base.py

🪛 Ruff (0.13.3)

holidays/holiday_base.py

205-205: Mutable class attributes should be annotated with typing.ClassVar

(RUF012)

235-235: Boolean-typed positional argument in function definition

(FBT001)

235-235: Boolean default positional argument in function definition

(FBT002)

236-236: Boolean-typed positional argument in function definition

(FBT001)

236-236: Boolean default positional argument in function definition

(FBT002)

798-798: Missing type annotation for *args

(ANN002)

957-957: Dynamically typed expressions (typing.Any) are disallowed in default

(ANN401)

957-957: Dynamically typed expressions (typing.Any) are disallowed in get

(ANN401)

1174-1174: Dynamically typed expressions (typing.Any) are disallowed in default

(ANN401)

1174-1174: Dynamically typed expressions (typing.Any) are disallowed in pop

(ANN401)

⏰ Context from checks skipped due to timeout of 300000ms. You can increase the timeout in your CodeRabbit configuration to a maximum of 15 minutes (900000ms). (2)

GitHub Check: Test docs build
GitHub Check: Build distribution

🔇 Additional comments (1)

holidays/holiday_base.py (1)

24-24: Remove unused Union import after completing migration.

Once the remaining Union usages on lines 385 and 1335 are migrated to PEP 604 syntax, this import can be removed.

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codecov · 2025-10-09T06:21:41Z

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (ad444fb) to head (cd48446).

Additional details and impacted files

@@            Coverage Diff            @@
##               dev     #2998   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files          305       305           
  Lines        18039     18005   -34     
  Branches      2329      2329           
=========================================
- Hits         18039     18005   -34

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Signed-off-by: Panpakorn Siripanich <19505219+PPsyrius@users.noreply.github.com>

sonarqubecloud · 2025-10-11T08:54:30Z

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.6% Duplication on New Code

See analysis details on SonarQube Cloud

PPsyrius added 2 commits October 9, 2025 12:41

Drop Python 3.9 support

a17e336

Modernize type annotations to PEP 604 pipe syntax

ae14ada

https://peps.python.org/pep-0604/

github-actions bot added ci script test labels Oct 9, 2025

PPsyrius added 3 commits October 10, 2025 11:06

Merge branch 'dev' into python_39_deprecation

b72ce58

Signed-off-by: Panpakorn Siripanich <19505219+PPsyrius@users.noreply.github.com>

PEP 604 migration for _move_holiday_forced

60d2a9c

Merge branch 'dev' into python_39_deprecation

cd48446

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