Switch default-python to use pyproject.toml & uv & dynamic_version in dev [hatchling backend]

[denik]

Changes

• Update default-python template to use pyproject.toml and uv (with hatchling).
• Get rid of dynamic version in setup.py and using dynamic_version attribute on artifacts instead (only in dev target and only on non-serverless clusters since serverless has fixed the issue with versions not being updated in the platform). See Add libs/patchwheel: insert dynamic version in whl #2427Implement dynamic_version attribute in artifacts section #2520

Why

Modern Python is based around pyproject.toml, not setup.py.

Using DAB-provided dynamic_version attribute allows keeping pyproject.toml simple and does not constraint what build backend users can choose.

Note, I've also considered using uv_build backend #3004 but it seems too early at the moment and hatchling is better tested with DABs.

Tests

Existing tests.

[Copilot]

Pull Request Overview

This PR modernizes the default‐python template by removing setup.py and in‐code versioning in favor of a pyproject.toml‐based hatchling build, switches the bundle to use uv build --wheel, and applies dynamic_version only on non‐serverless dev targets.

• Drop __version__ and setup.py.tmpl, introduce pyproject.toml.tmpl with hatchling wheel config.
• Update databricks.yml.tmpl to run uv build --wheel and conditionally enable dynamic_version for dev.
• Refresh acceptance tests (out.*, check_output.py) and update NEXT_CHANGELOG.md.

Reviewed Changes

Copilot reviewed 18 out of 18 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
libs/template/.../init.py	Remove hardcoded __version__ assignment
libs/template/.../pyproject.toml.tmpl	Add [project] metadata and hatchling wheel build config
libs/template/.../databricks.yml.tmpl	Use uv build --wheel and conditional dynamic_version in dev
acceptance/.../check_output.py	Replace literal upload check with regex-based UPLOADING_WHL
NEXT_CHANGELOG.md	Document new default-python template changes

Comments suppressed due to low confidence (2)

NEXT_CHANGELOG.md:6

• [nitpick] The backslash in dynamic\_version is only needed to escape Markdown italics. For clarity, wrap it in inline code: dynamic_version.

* Switch default-python template to use pyproject.toml + dynamic\_version in dev target. uv is now required. ([#3042](https://github.com/databricks/cli/pull/3042))

libs/template/templates/default-python/template/{{.project_name}}/databricks.yml.tmpl:8

• The conditional artifacts: block under the dev target may be misaligned in indentation and could break YAML parsing. Align the artifacts: and python_artifact: keys with the workspace: block under dev.

{{ if $with_python }}

[Copilot]

In is_printable_line, using UPLOADING_WHL.match(line) only matches at the start and will miss indented or prefixed upload lines. Consider using search() in both the function and the regex (e.g., re.compile("Uploading .*\.whl")) or anchoring appropriately.

Suggested change

	UPLOADING_WHL=re.compile("Uploading .*whl")
	UPLOADING_WHL=re.compile(r"Uploading .*\.whl")

[pietern]

Nice!