#407 Back to the future, destination 3.14

Python Bytes

Topics covered in this episode:

• Python 3.14.0 alpha 1 is now available
• uv supports dependency groups
• dive: A tool for exploring each layer in a docker image
• pytest-metadata
• Extras
• Joke

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Michael #1: Python 3.14.0 alpha 1 is now available

• First of seven planned alpha releases.
• Many new features for Python 3.14 are still being planned and written. Among the new major new features and changes so far:
  • PEP 649: deferred evaluation of annotations
  • Improved error messages

Brian #2: uv supports dependency groups

• we covered dependency groups in episode 406
• as of 0.4.27, uv supports dependency groups
• docs show how to add dependencies with uv add --group
  • also “The --dev, --only-dev, and --no-dev flags are equivalent to --group dev, --only-group dev, and --no-group dev respectively.”
• To install a group, uv pip install --group doesn’t work yet.
  • It’s waiting for PyPA to decide on an interface for pip, and uv pip will use that interface.
• But sync works.

  $ uv init # create a pyproject.toml $ uv add --group foo pytest $ uv venv # create venv $ uv sync --group foo # will install all dependencies, including group "foo" 

Michael #3: dive: A tool for exploring each layer in a docker image

• via Mike Fiedler
• Features:
  • Show Docker image contents broken down by layer
  • Indicate what's changed in each layer
  • Estimate "image efficiency"
  • Quick build/analysis cycles
  • CI Integration

Brian #4: pytest-metadata

• An incredibly useful plugin for adding, you guessed it, metadata, to your pytest results.
• Required for pytest-html but also useful on it’s own
• Adds metadata to
  • text output with --verbose
  • xml output when using --junit-xml, handy for CI systems that support junit.xml
• Other plugins depend on this and report in other ways, such as pytest-html
• By default, already grabs
  • Python version
  • Platform info
  • List of installed packages
  • List of installed pytest plugins
• You can add your own metadata
• You can access all metadata (and add to it) from tests, fixtures, and hook functions via a metadata fixture.
• This is in the Top pytest Plugins list, currently #5.

Extras

Brian:

• I’ve started filtering deprecated plugins from the pytest plugin list.
• I’m also going to start reviewing the list and pulling out interesting plugins as the topic of the next season of Test & Code.

Michael:

• Pillow 11 is out
• pip install deutschland
• Talk Python has a dedicated blog, please subscribe!

Joke: Dog names