Add support for Python 3.12

[hugovk]

Tracking issue for getting the pieces into place to:

• release wheels for Python 3.12.0 beta in Pillow 10.0.0, released on 2023-07-01
• support Python 3.12.0 final in Pillow 10.1.0, released on 2023-10-15

TODO

• Wait for 3.12.0, expected Monday, 2023-10-02
• Update https://github.com/python-pillow/pillow-wheels https://github.com/python-pillow/Pillow/tree/main/wheels
• #7280, (#7285) Add Trove classifier, update setup.py version check, add to tox.ini, update Python support table
• Update CI targets table

Non-blockers

• Wait for 3.12.0 on GHA:
  • Replace 3.12-dev with 3.12 on GHA:
  • 3.12-dev should pick up 3.12.0 on-flight fairly soon after release, and be added to cached images later
• Wait for 3.12.0 on AppVeyor: Python 3.12 appveyor/ci#3879
  • Replace 3.11 with 3.12 on AppVeyor: Updated AppVeyor to Python 3.12 #7508
• Wait for 3.12.0 on Travis CI: https://travis-ci.community/t/add-python-3-12/14006?u=hugovk
  • this is base Python, we use Docker for building wheels
  • Replace 3.11 with 3.12 on Travis CI: Update Travis CI to Python 3.12 and Ubuntu 22.04 Jammy Jellyfish #7501

References:

• Pillow milestones
• PEP 693 – Python 3.12 Release Schedule
• Add support for Python 3.11 #6575

[radarhere]

deadsnakes decided not to support Python 3.12 on Bionic, the last 32-bit Ubuntu. We've discussed dropping support for 32-bit briefly before, so the simplest thing is for us to not release 32-bit Linux Python 3.12 wheels.

[hugovk]

That should be fine.

Looking at a couple of projects:

We (NumPy) will continue to test (but not provide wheels for) 32-bit linux.

We [pyca/cryptography] stopped testing on 32-bit Linux, and stopped building 32-bit Linux wheels several years ago, and that produced no problems.

https://discuss.python.org/t/dropping-32-bit-packages/5476/16?u=hugovk

---

Looking at some numbers, here's a week's worth of Pillow file downloads from PyPI, fetched using https://github.com/ofek/pypinfo:

pypinfo --days 7 --limit 1000 pillow version file

1000.txt

Filtering for the most recent release, for Python 3.11, and Linux (grep "9.5.0-cp311.*linux" 1000.txt) shows a very small number for i686:

version	file	download_count	percentage
9.5.0	Pillow-9.5.0-cp311-cp311-manylinux_2_28_x86_64.whl	219,628	91.71 %
9.5.0	Pillow-9.5.0-cp311-cp311-manylinux_2_28_aarch64.whl	7,407	3.09 %
9.5.0	Pillow-9.5.0-cp311-cp311-musllinux_1_1_x86_64.whl	5,810	2.43 %
9.5.0	Pillow-9.5.0-cp311-cp311-manylinux_2_17_x86_64.manylinux2014_x86_64.whl	5,233	2.19 %
9.5.0	Pillow-9.5.0-cp311-cp311-musllinux_1_1_aarch64.whl	771	0.32 %
9.5.0	Pillow-9.5.0-cp311-cp311-manylinux_2_17_aarch64.manylinux2014_aarch64.whl	405	0.17 %
9.5.0	Pillow-9.5.0-cp311-cp311-manylinux_2_17_i686.manylinux2014_i686.whl	226	0.09 %
	total	239,480	100.00 %

[hugovk]

Whilst we're here, Windows is quite low for win32:

version	file	download_count	percentage
9.5.0	Pillow-9.5.0-cp311-cp311-win_amd64.whl	150,653	98.82 %
9.5.0	Pillow-9.5.0-cp311-cp311-win32.whl	1,580	1.04 %
9.5.0	Pillow-9.5.0-cp311-cp311-win_arm64.whl	225	0.15 %
	total	152,458	100.00 %

[wiredfool]

I'd say just drop the 32 bit builds, especially for new pythons.

[hugovk]

Sounds good.

So let's not create 32-bit wheels for 3.12. Do we still want to test 32-bit for 3.12?

The next Pillow 10.0.0 is a major bump so it's a good opportunity to drop things:

• For 3.11, shall we drop 32-bit wheels and/or testing?

• And older ones, 3.10-3.8?

For Linux, the *i686.whl numbers are very low for all versions (0.01% - 0.09%):

Details

version	file	download_count	percentage
9.5.2	Pillow-9.5.0-cp311-cp311-manylinux_2_28_x86_64.whl	219,628	91.71 %
9.5.2	Pillow-9.5.0-cp311-cp311-manylinux_2_28_aarch64.whl	7,407	3.09 %
9.5.2	Pillow-9.5.0-cp311-cp311-musllinux_1_1_x86_64.whl	5,810	2.43 %
9.5.2	Pillow-9.5.0-cp311-cp311-manylinux_2_17_x86_64.manylinux2014_x86_64.whl	5,233	2.19 %
9.5.2	Pillow-9.5.0-cp311-cp311-musllinux_1_1_aarch64.whl	771	0.32 %
9.5.2	Pillow-9.5.0-cp311-cp311-manylinux_2_17_aarch64.manylinux2014_aarch64.whl	405	0.17 %
9.5.2	Pillow-9.5.0-cp311-cp311-manylinux_2_17_i686.manylinux2014_i686.whl	226	0.09 %
	total	239,480	100 %
9.5.2	Pillow-9.5.0-cp310-cp310-manylinux_2_28_x86_64.whl	788,288	91.90 %
9.5.2	Pillow-9.5.0-cp310-cp310-manylinux_2_17_x86_64.manylinux2014_x86_64.whl	46,996	5.48 %
9.5.2	Pillow-9.5.0-cp310-cp310-manylinux_2_28_aarch64.whl	13,842	1.61 %
9.5.2	Pillow-9.5.0-cp310-cp310-musllinux_1_1_x86_64.whl	6,597	0.77 %
9.5.2	Pillow-9.5.0-cp310-cp310-musllinux_1_1_aarch64.whl	934	0.11 %
9.5.2	Pillow-9.5.0-cp310-cp310-manylinux_2_17_aarch64.manylinux2014_aarch64.whl	882	0.10 %
9.5.2	Pillow-9.5.0-cp310-cp310-manylinux_2_17_i686.manylinux2014_i686.whl	224	0.03 %
	total	857,763	100 %
9.5.2	Pillow-9.5.0-cp39-cp39-manylinux_2_28_x86_64.whl	910,193	84.64 %
9.5.2	Pillow-9.5.0-cp39-cp39-manylinux_2_17_x86_64.manylinux2014_x86_64.whl	137,166	12.75 %
9.5.2	Pillow-9.5.0-cp39-cp39-manylinux_2_28_aarch64.whl	15,810	1.47 %
9.5.2	Pillow-9.5.0-cp39-cp39-manylinux_2_17_aarch64.manylinux2014_aarch64.whl	7,066	0.66 %
9.5.2	Pillow-9.5.0-cp39-cp39-musllinux_1_1_x86_64.whl	4,184	0.39 %
9.5.2	Pillow-9.5.0-cp39-cp39-musllinux_1_1_aarch64.whl	542	0.05 %
9.5.2	Pillow-9.5.0-cp39-cp39-manylinux_2_17_i686.manylinux2014_i686.whl	462	0.04 %
	total	1,075,423	100 %
9.5.2	Pillow-9.5.0-cp38-cp38-manylinux_2_28_x86_64.whl	924,301	51.40 %
9.5.2	Pillow-9.5.0-cp38-cp38-manylinux_2_17_x86_64.manylinux2014_x86_64.whl	856,048	47.60 %
9.5.2	Pillow-9.5.0-cp38-cp38-manylinux_2_17_aarch64.manylinux2014_aarch64.whl	7,569	0.42 %
9.5.2	Pillow-9.5.0-cp38-cp38-manylinux_2_28_aarch64.whl	7,523	0.42 %
9.5.2	Pillow-9.5.0-cp38-cp38-musllinux_1_1_x86_64.whl	2,343	0.13 %
9.5.2	Pillow-9.5.0-cp38-cp38-musllinux_1_1_aarch64.whl	355	0.02 %
9.5.2	Pillow-9.5.0-cp38-cp38-manylinux_2_17_i686.manylinux2014_i686.whl	241	0.01 %
	total	1,798,380	100 %

For Windows, *win32.whl are a bigger proportion but still low (0.90% - 5.63%):

Details

version	file	download_count	percentage
9.5.2	Pillow-9.5.0-cp311-cp311-win_amd64.whl	150,653	98.82 %
9.5.2	Pillow-9.5.0-cp311-cp311-win32.whl	1,580	1.04 %
9.5.2	Pillow-9.5.0-cp311-cp311-win_arm64.whl	225	0.15 %
	total	152,458	100.00 %
9.5.2	Pillow-9.5.0-cp310-cp310-win_amd64.whl	198,304	99.10 %
9.5.2	Pillow-9.5.0-cp310-cp310-win32.whl	1,801	0.90 %
	total	200,105	100.00 %
9.5.2	Pillow-9.5.0-cp39-cp39-win_amd64.whl	89,231	98.12 %
9.5.2	Pillow-9.5.0-cp39-cp39-win32.whl	1,710	1.88 %
	total	90,941	100.00 %
9.5.2	Pillow-9.5.0-cp38-cp38-win_amd64.whl	71,998	94.37 %
9.5.2	Pillow-9.5.0-cp38-cp38-win32.whl	4,298	5.63 %
	total	76,296	100 %

[radarhere]

python-pillow/pillow-wheels#383 has added Python 3.12 macOS and Linux wheels, excluding 32-bit wheels, and albeit without fribidi, harfbuzz and raqm on macOS until #7167 is resolved.