Update from setup.py to pyproject.toml

[jsf9k]

🗣 Description

This pull request updates our project packaging configuration from using a setup.py file to using a pyproject.toml file with a setuptools build backend.

See also cisagov/skeleton-generic#235.

💭 Motivation and context

Resolves #163. Resolves #136.

🧪 Testing

All automated tests pass.

✅ Pre-approval checklist

• This PR has an informative and human-readable title.
• Changes are limited to a single goal - eschew scope creep!
• All relevant type-of-change labels have been added.
• I have read the CONTRIBUTING document.
• These code changes follow cisagov code standards.
• All new and existing tests pass.

[jsf9k]

@mcdonnnj - I'm not sure what kind of version bump to apply here, if any.

[jsf9k]

The flake8 config could be moved to the pyproject.toml file as well, but that would require the flake8-pyproject Python package. There is also the complication that the flake8 configuration comes from upstream. See cisagov/skeleton-generic#234.

The bandit config is only used when pre-commit runs bandit against the Python test code; otherwise, we use the default configuration for bandit. For completeness, also see cisagov/skeleton-generic#233.

[jsf9k]

I realize that we want wheel and pip to be the latest versions, but should we now remove setuptools from setup-env? If so then this would be an upstream change in cisagov/skeleton-generic.

[dav3r]

This all looks like a solid start to me. Thanks for getting us switched over to pyproject.toml. 🎉

[Copilot]

Pull Request Overview

This pull request migrates the project from a setup.py-based build configuration to a modern pyproject.toml-based configuration using the Hatchling build backend. This modernization consolidates configuration files and follows current Python packaging best practices (PEP 517/518).

• Migrates from setup.py to pyproject.toml with Hatchling as the build backend
• Consolidates pytest.ini and .isort.cfg configurations into pyproject.toml
• Updates GitHub labeler configuration to reference the new configuration file

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
setup.py	Removed legacy setup.py file (116 lines)
pytest.ini	Removed standalone pytest configuration file
.isort.cfg	Removed standalone isort configuration file
pyproject.toml	Added comprehensive project configuration including build system, dependencies, tool configurations, and metadata
.github/labeler.yml	Updated file references from setup.py, .isort.cfg, and pytest.ini to pyproject.toml

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[jsf9k]

@mcdonnnj - Any thoughts here? Are you still researching the current landscape of build backends?

[jsf9k]

In this PR I moved the isort config to pyproject.toml, but just now I realized that this file is actually inherited from cisagov/skeleton-generic. As a result I have dropped commit 1ae44fe.

Do we want to leave the .isort.cfg file as it is in cisagov/skeleton-generic or create a pyproject.toml in that repo to contain that tool's configuration? I'm for the latter, since that would make things cleaner here.

[dav3r]

In a way you already do, since .isort.cfg is present. isort only sorts Python imports. That sounds pretty Python-specific to me.

LOL, I forgot about that. In that case, I agree with your plan to replace .isort.cfg with a section in pyproject.toml.

[jsf9k]

@mcdonnnj - At one point you said that if we used setuptools as the Python build backend then we shouldn't get rid of the setup.py file. Why was that? I don't think the setup.py file is necessary unless you're compiling native code. If you insist, I could add a simple setup.py like this as a placeholder:

import setuptools

setuptools.setup()

I don't see the point of that, though.

Also, it appears that hatchling doesn't support native code associated with Python libraries very well. Maybe that's one reason to use setuptools instead. As far as I can tell, setuptools is still the most common build backend and a lot of folks are saying the fact that the documentation appears to promote hatchling instead is misleading. Projects like numpy that have a lot of compiled native code tend to use something like PDM.

I'm kind of of the opinion that until we have native extensions it's a tossup between hatchling and setuptools.

I think this PR would change only slightly if we used setuptools as the build backend instead of hatchling. I'm happy to make those changes if that's where you're leaning.

[jsf9k]

FYI, here are the necessary changes for moving to setuptools as the build backend:

diff --git a/pyproject.toml b/pyproject.toml
index 370ba01..727434b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,9 +1,9 @@
 # For more information about configuring project metadata for the
-# hatch build backend, please see
-# https://hatch.pypa.io/latest/config/metadata/
+# setuptools build backend, please see
+# https://setuptools.pypa.io/en/latest/userguide/pyproject_config.html
 [build-system]
-build-backend = "hatchling.build"
-requires = ["hatchling"]
+build-backend = "setuptools.build_meta"
+requires = ["setuptools"]
 
 [project]
 authors = [
@@ -38,11 +38,10 @@ dependencies = [
     "schema",
 ]
 description = "Example Python library"
-dynamic = ["version"]
+dynamic = ["readme", "version"]
 keywords = ["skeleton"]
 license = "CC0-1.0"
 name = "example"
-readme = "README.md"
 requires-python = ">=3.9"
 
 [project.optional-dependencies]
@@ -74,12 +73,12 @@ issues = "https://github.com/cisagov/skeleton-python-library/issues"
 mission = "https://www.cisa.gov/cybersecurity"
 source = "https://github.com/cisagov/skeleton-python-library"
 
-[tool.hatch.version]
-# Versions should comply with PEP440
-path = "src/example/_version.py"
-
 [tool.pytest.ini_options]
 # Increase verbosity, display extra test summary info for tests that
 # did not pass, display code coverage results, and enable debug
 # logging.
 addopts = "--verbose -ra --cov --log-cli-level=DEBUG"
+
+[tool.setuptools.dynamic]
+readme = {file = ["README.md"], content-type = "text/markdown"}
+version = {attr = "example._version.__version__"}

[jsf9k]

In case it helps, this is how I cope with the current state of Python packaging:

[mcdonnnj]

@mcdonnnj - At one point you said that if we used setuptools as the Python build backend then we shouldn't get rid of the setup.py file. Why was that? I don't think the setup.py file is necessary unless you're compiling native code.

Keeping the setup.py file is the recommendation of PyPA in their guide to modernizing setup.py projects and it has not been deprecated.

[jsf9k]

@mcdonnnj - At one point you said that if we used setuptools as the Python build backend then we shouldn't get rid of the setup.py file. Why was that? I don't think the setup.py file is necessary unless you're compiling native code.

Keeping the setup.py file is the recommendation of PyPA in their guide to modernizing setup.py projects and it has not been deprecated.

Yes, in the first link they say it can coexist but nowhere do they say it must be present. My point is that if everything can be moved into the pyproject.toml file (as I show above) then there is no need for it. It is just a dumb placeholder file.

[jsf9k]

I don't think the setup.py file is necessary unless you're compiling native code.

Actually, it isn't even necessary if you're compiling native code. So I don't see any reason to keep a setup.py file around.

[jsf9k]

FYI, here are the necessary changes for moving to setuptools as the build backend:

diff --git a/pyproject.toml b/pyproject.toml
index 370ba01..727434b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,9 +1,9 @@
 # For more information about configuring project metadata for the
-# hatch build backend, please see
-# https://hatch.pypa.io/latest/config/metadata/
+# setuptools build backend, please see
+# https://setuptools.pypa.io/en/latest/userguide/pyproject_config.html
 [build-system]
-build-backend = "hatchling.build"
-requires = ["hatchling"]
+build-backend = "setuptools.build_meta"
+requires = ["setuptools"]
 
 [project]
 authors = [
@@ -38,11 +38,10 @@ dependencies = [
     "schema",
 ]
 description = "Example Python library"
-dynamic = ["version"]
+dynamic = ["readme", "version"]
 keywords = ["skeleton"]
 license = "CC0-1.0"
 name = "example"
-readme = "README.md"
 requires-python = ">=3.9"
 
 [project.optional-dependencies]
@@ -74,12 +73,12 @@ issues = "https://github.com/cisagov/skeleton-python-library/issues"
 mission = "https://www.cisa.gov/cybersecurity"
 source = "https://github.com/cisagov/skeleton-python-library"
 
-[tool.hatch.version]
-# Versions should comply with PEP440
-path = "src/example/_version.py"
-
 [tool.pytest.ini_options]
 # Increase verbosity, display extra test summary info for tests that
 # did not pass, display code coverage results, and enable debug
 # logging.
 addopts = "--verbose -ra --cov --log-cli-level=DEBUG"
+
+[tool.setuptools.dynamic]
+readme = {file = ["README.md"], content-type = "text/markdown"}
+version = {attr = "example._version.__version__"}

Please see commit 461f872.

[jsf9k]

@mcdonnnj - At one point you said that if we used setuptools as the Python build backend then we shouldn't get rid of the setup.py file. Why was that? I don't think the setup.py file is necessary unless you're compiling native code. If you insist, I could add a simple setup.py like this as a placeholder:

import setuptools

setuptools.setup()

I don't see the point of that, though.

Also, it appears that hatchling doesn't support native code associated with Python libraries very well. Maybe that's one reason to use setuptools instead. As far as I can tell, setuptools is still the most common build backend and a lot of folks are saying the fact that the documentation appears to promote hatchling instead is misleading. Projects like numpy that have a lot of compiled native code tend to use something like PDM.

I'm kind of of the opinion that until we have native extensions it's a tossup between hatchling and setuptools.

I think this PR would change only slightly if we used setuptools as the build backend instead of hatchling. I'm happy to make those changes if that's where you're leaning.

Please see commit 461f872.

[dav3r]

This all looks reasonable to me. 👍

[jsf9k]

I realize that we want wheel and pip to be the latest versions, but should we now remove setuptools from setup-env? If so then this would be an upstream change in cisagov/skeleton-generic.

This comment is no longer applicable since we moved to using setuptools as our build backend.