Python versioning¶

Currently py-template is set to support Python versions 3.9 or above according to numpy's NEP29 (which is not a standard per-se, but due to large influence of the package it is followed by many projects, especially in scientific Python).

Currently tests are run locally using Python version of your choosing (but greater than 3.9), while the code checkers run on versions 3.9.x or 3.10.x (due to lack of support of 3.11 from pytype).

Within GitHub pipelines we have currently pinned tests to run across the following version matrix (and across Linux and MacOS for each):

• 3.9 (lowest supported version you should target)
• 3.10
• 3.11

This approach is well-suited for libraries and frameworks, which should provide support for larger set of dependencies, but might be unnecessary for standalone applications (like Dockerized FastAPI service).

If you are not developing a library we advice to use only one version of Python (preferably 3.10 due to the ease of setup and no conflicts) and one OS (usually linux locally and ubuntu within pipeline).

Rest of the document describes how to adjust config to Python 3.10 and Ubuntu and is tailored to standalone applications

1. Adjusting pyproject.toml¶

Modify .pyproject.toml file under DEPENDENCIES section as shown below:

###############################################################################
#
#                               DEPENDENCIES
#
###############################################################################

[tool.poetry.dependencies]
# Only change here
python="~=3.10"

After that we need to adjust ruff settings to tailor any automated fixers and code checkers to our new version.

One can do it under FIX SETTINGS section via single line change:

###############################################################################
#
#                                FIX SETTINGS
#
###############################################################################

[tool.black]
line-length = 79

[tool.ruff]
# Only change here
target-version = "py310"

2. Adjusting GitHub Actions¶

Modify .github/workflows/python-tests.yml and matrix specifically as shown below (you can simply remove the OSes/versions you are not interested in):

jobs:
  tests:
    if: ${{ ! contains(github.repository, 'template') }}
    strategy:
      matrix:
        py:
          - '3.10'
        os:
          - ubuntu-latest
    name: >
      ${{ matrix.os }} | py-${{ matrix.py }}
    runs-on: ${{ matrix.os }}

These two steps should be enough to adjust to specific version and lower costs/entry barrier by only testing across single version and OS.