Migrate settings from setup.py/setup.cfg to pyproject.toml

[seisman]

As mentioned in #1797 (comment), it's better to remove setup.py/setup.cfg and move all project metadata and packaging/buiding to pyproject.toml.

Here are some related resources I found on the internet:

PEPs

• PEP 517 – A build-system independent format for source trees
• PEP 518 – Specifying Minimum Build System Requirements for Python Projects
• PEP 621 – Storing project metadata in pyproject.toml
• PEP 631 – Dependency specification in pyproject.toml based on PEP 508

Tools

General

• https://chadsmith.dev/python-packaging/
• https://bernat.tech/posts/pep-517-and-python-packaging/
• https://bernat.tech/posts/pep-517-518/

Setuptools

• https://setuptools.pypa.io/en/latest/userguide/pyproject_config.html
• Discussion: support for pyproject.toml configuration pypa/setuptools#1688
• https://discuss.python.org/t/help-testing-experimental-features-in-setuptools/13821
• [FR] Implement PEP 660 -- Editable Installations pypa/setuptools#2816

Poetry

• https://python-poetry.org/
• https://github.com/mtkennerly/poetry-dynamic-versioning
• WIP: Setup poetry in pyproject.toml #1055
• Support for PEP 621 python-poetry/roadmap#3

Flit

• https://flit.pypa.io/en/latest/
• RFE: functionality to set __version__ from scm automatically pypa/flit#257

[weiji14]

So what's the next step after #1845? Migrating the flake8 configuration in setup.cfg to pyproject.toml (xref #948 (comment))? I see you've discovered flakeheaven at flakeheaven/flakeheaven#68, so we could move from flake8 -> flakeheaven once there's a proper conda-forge package?