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

Release Notes

Breaking Changes
- Dropped support for Python 3.9. Minimum required version is now Python 3.10.
Chores
- Updated type hints across the library to use modern Python syntax.
- Updated CI/CD pipeline and development tooling to target Python 3.10+.
- Updated dependencies and development requirements.

Walkthrough

Removed Python 3.9 support and raised project/tooling targets to >=3.10; migrated many typing annotations from typing.Optional/Union to PEP 604 union syntax (X | None, A | B). Mostly signature and import cleanups; no runtime logic changes.

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`	Dropped Python 3.9 from test matrices; updated requires-python to >=3.10; switched pyupgrade/ruff targets to 3.10+; adjusted test dependency pinning and removed zipp pin.
Core framework & utilities `holidays/holiday_base.py`, `holidays/observed_holiday_base.py`, `holidays/utils.py`, `holidays/registry.py`, `holidays/ical.py`, `holidays/mixins/child_entity.py`	Replaced `Optional`/`Union` typings 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 and 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 add* helpers and internal APIs 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 method/field annotations to use `
Scripts & tests `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

Update ruff configuration: add flake8-boolean-trap (FBT) errors check #3007 — Overlapping signature/type-hint edits and pyproject/tooling changes; likely to touch the same APIs (observed rules, core signatures).
Add _add_observed/_move_holiday's force_observed support #2986 — Modifies observed-holiday APIs (_add_observed/_move_holiday); strong overlap with observed_holiday_base.py signature changes.
Switch to Python 3.14 #2997 — CI/tooling changes that also adjust supported Python versions and workflow/test-matrix configuration.

Suggested reviewers

arkid15r
KJhellico

Pre-merge checks and finishing touches

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	You can run `@coderabbitai generate docstrings` to improve docstring coverage.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title Check	✅ Passed	The title "Drop Python 3.9 support" directly and clearly summarizes the primary change in this changeset. The raw_summary confirms that Python 3.9 has been removed from the CI workflow test matrix and throughout the codebase (pyproject.toml, tox.ini), and the PR objectives align perfectly with dropping support for this Python version. The title is concise, specific, and immediately communicates the main change without ambiguity.
Description Check	✅ Passed	The description is clearly related to the changeset, providing meaningful context for the changes. It explains the rationale (Python 3.9 EOL in October 2025), outlines the three main categories of changes (dropping Python 3.9 support, upgrading to Python 3.10 syntax with PEP 604, and removing zipp dependencies), and references supporting documentation. All points in the description correspond to actual changes reflected in the raw_summary—from CI/configuration updates to widespread type hint migrations across the codebase.

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📥 Commits

Reviewing files that changed from the base of the PR and between 8ad5957 and 0dad4d4.

📒 Files selected for processing (3)

.github/workflows/ci-cd.yml (0 hunks)
.pre-commit-config.yaml (1 hunks)
requirements/dev.txt (0 hunks)

💤 Files with no reviewable changes (2)

.github/workflows/ci-cd.yml
requirements/dev.txt

⏰ 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). (4)

GitHub Check: Test Python 3.13 on ubuntu-latest
GitHub Check: Test Python 3.10 on windows-latest
GitHub Check: Test Python 3.14 on windows-latest
GitHub Check: Test Python 3.12 on windows-latest

🔇 Additional comments (1)

.pre-commit-config.yaml (1)

26-26: Correct target-version bump for pyupgrade.

The update from --py39-plus to --py310-plus properly aligns pyupgrade with the project's new minimum Python version (3.10+), enabling transformation to PEP 604 union syntax and other 3.10+ idioms across the codebase.

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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 (53853df) to head (0dad4d4).

Additional details and impacted files

@@            Coverage Diff            @@
##               dev     #2998   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files          306       306           
  Lines        18062     18028   -34     
  Branches      2333      2333           
=========================================
- Hits         18062     18028   -34

☔ View full report in Codecov by Sentry.
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Signed-off-by: Panpakorn Siripanich <[email protected]>

sonarqubecloud · 2025-10-24T09:33:46Z

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 <[email protected]>

PEP 604 migration for _move_holiday_forced

60d2a9c

Merge branch 'dev' into python_39_deprecation

cd48446

mj0nez mentioned this pull request Oct 12, 2025

chore: remove support of python 3.9 due to EOL mj0nez/bdew-datetimes#265

Draft

PPsyrius added 7 commits October 13, 2025 09:50

Merge branch 'dev' into python_39_deprecation

7dd88bf

Merge branch 'dev' into python_39_deprecation

fadaec7

Merge branch 'dev' into python_39_deprecation

69ef6b0

Merge branch 'dev' into python_39_deprecation

ef59649

Merge branch 'dev' into python_39_deprecation

30c3cbc

Merge branch 'dev' into python_39_deprecation

8ad5957

Merge branch 'dev' into python_39_deprecation

0dad4d4

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Summary by CodeRabbit

Release Notes

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Estimated code review effort

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