What's the problem this feature will solve?

A typical tox file for me consists largely of two types of environments:

• tests that run under a matrix
• tools like coverage or mypy that run under a common python version

So currently, my tox files are littered with:

# Keep base_python in-sync with .python-version-default
base_python = 3.13

It would be cool, if I could specify a file here like we can in GitHub Actions:

      - uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
        with:
          python-version-file: .python-version-default

Describe the solution you'd like

Sorry for the ini:

[testenv:coverage-combine]
base_python_file = .python-version-default
depends = *-tests*
skip_install = true
deps = coverage
commands = coverage combine

Alternative Solutions

¯\_(ツ)_/¯

Additional context

The depends patterns allowed me to get rid of repetitive boilerplate, so this is kinda sticking out now. :)