Migrate setup.py to a PEP 621 pyproject.toml #268

Part of the repository modernization effort.

Background

setup.py is the only source of package metadata. The version string 0.32.0 exists in four places:

• setup.py:17
• docs/conf.py — version = '0.32' and release = '0.32.0'
• .cz.yaml:5
• flake.nix:68

pyproject.toml holds only a [build-system] table. setup.cfg holds only the flake8 line length.

Warning: commitizen must keep working

.cz.yaml drives the release bump:

---
commitizen:
  name: cz_conventional_commits
  tag_format: v$version
  version: 0.32.0
  version_files:
  - setup.py
  - docs/conf.py

version_files does a literal replace of the version string. If setup.py is deleted, the entry must move to the new version source. Run cz bump --dry-run and confirm the result before you merge.

Note the pre-existing gap: the short version = '0.32' line in docs/conf.py does not match the full 0.32.0 string. commitizen does not bump it today.

Warning: keep README.rst

README.rst is a symlink to docs/intro.rst. docs/intro.rst is a Sphinx source file in reStructuredText.

Do not convert README.rst to Markdown. The conversion breaks the Sphinx build.

A PEP 621 readme = "README.rst" field reads whatever the path resolves to at build time. That is the symlink in a local build. That is the pandoc-built file in the publish workflow. The behavior matches setup.py today. .github/workflows/publish.yml needs no change for this issue.

Proposed pyproject.toml

[build-system]
requires = ["setuptools>=68"]
build-backend = "setuptools.build_meta"

[project]
name = "python-binary-memcached"
dynamic = ["version"]
description = "A pure python module to access memcached via its binary protocol with SASL auth support"
readme = "README.rst"
requires-python = ">=3.10"
license = { text = "MIT" }
authors = [
    { name = "Jayson Reis", email = "santosdosreis@gmail.com" },
]
classifiers = [
    "Development Status :: 4 - Beta",
    "License :: OSI Approved :: MIT License",
    "Operating System :: OS Independent",
    "Programming Language :: Python :: 3 :: Only",
    "Programming Language :: Python :: 3.10",
    "Programming Language :: Python :: 3.11",
    "Programming Language :: Python :: 3.12",
    "Programming Language :: Python :: 3.13",
    "Programming Language :: Python :: 3.14",
]
dependencies = [
    "uhashring",
]

[project.urls]
Homepage = "https://github.com/jaysonsantos/python-binary-memcached"
Repository = "https://github.com/jaysonsantos/python-binary-memcached"
Documentation = "https://python-binary-memcached.readthedocs.org"
Changelog = "https://github.com/jaysonsantos/python-binary-memcached/blob/main/CHANGELOG.md"

[tool.setuptools]
packages = ["bmemcached", "bmemcached.client"]

[tool.setuptools.dynamic]
version = { attr = "bmemcached.__version__" }

Warning: where to put __version__

Add __version__ = "0.32.0" as the first line of bmemcached/__init__.py. Put it before the bmemcached.client import.

setuptools reads the attr: target from the module AST. It falls back to a real import when the AST read fails. A plain literal at the top avoids an import of bmemcached.client inside the isolated build environment. That import needs uhashring to be present already.

Acceptance criteria

• pyproject.toml holds the [project] table above.
• bmemcached/__init__.py declares __version__ = "0.32.0" on the first line.
• setup.py and setup.cfg are deleted.
• .cz.yaml version_files lists bmemcached/__init__.py and docs/conf.py. It no longer lists setup.py.
• cz bump --dry-run finds and replaces the version string.
• python -m build --sdist --wheel --outdir dist/ . succeeds.
• twine check dist/* passes.
• The built sdist holds README.rst and CHANGELOG.md. Check MANIFEST.in.
• AGENTS.md:10,18 points at pyproject.toml. It no longer points at setup.py or setup.cfg.
• The pull request text states that flake.nix:68 keeps a manual copy of the version.

Files to change

pyproject.toml, bmemcached/__init__.py, setup.py (delete), setup.cfg (delete), .cz.yaml, AGENTS.md, MANIFEST.in (check only).

Order

Do the minimum-version issue first. Do this issue before the ruff issue and the test-dependency issue. All three change pyproject.toml.

If setup.cfg is still needed for flake8, delete it in the ruff issue instead.