tox.ini

# This demonstrates using tox to test different Python versions and different library versions on select Python versions.

# TODO: use asdf, pyenv, Dockerfile to install many py versions

# Dependencies: aiohttp
# Dev dependencies: pytest pytest-asyncio pytest-cov tox tox-pyenv
[tox]
envlist =
# The oldest Python version we support
# 3.7 is EOL and 3.8 only has 1 more year of security updates
# Test 3.8 with an old version of dependencies
  py38
  py38-oldaiohttp
  py39
  py310
  py311
# The latest Python version.
# Test it with an old version of dependencies
  py311-oldaiohttp
  py311-olderaiohttp
# The future :)
  py312

[testenv]
# Example here: https://stackoverflow.com/questions/57024579/tox-ini-environment-with-multiple-dependencies
# 'deps' can also point to any number of requirements.txt or pyproject.toml files.  
# Here, we list all dependencies without using other files for the sake of simplicity.
deps:
# Install the latest version of aiohttp for all Python versions, with 2 exceptions.
  aiohttp
  tox-pyenv
  pytest
  pytest-asyncio
  pytest-cov 
# For the two Python versions where we'll support old libraries, install the old dependencies.
# Old aiohttp versions have several CVEs, especially <=3.8.6
# https://security.snyk.io/package/pip/aiohttp
  py39-oldaiohttp: aiohttp<3.9
  py311-oldaiohttp: aiohttp<3.9
  py311-olderaiohttp: aiohttp<3.8

# Run unit tests with pytest.
# Pytest can also run unit tests that only use the builtin unittest module.
commands = pytest --cov-report term --cov-report html --cov=. --capture=no --durations=0 --durations-min=0.01 --log-cli-level=CRITICAL {posargs} tox_example.py

tox_example.py

import sys

import aiohttp
import pytest

@pytest.mark.asyncio
async def test_aiohttp_version():
    assert isinstance(aiohttp.__version__, str)
    if sys.version_info <= (3,8) or sys.version_info >= (3, 11):
        assert aiohttp.__version__ in ["3.9.3", "3.8.6", "3.7.4.post0"]
    else:
        assert aiohttp.__version__ == "3.9.3" or aiohttp.__version__.startswith("4.")

def main():
    print("AIOHTTP version is", aiohttp.__version__)

if __name__ == "__main__":
    main()

The first revision is a simple tox.ini file, the next revisions will show how to test more versions of Python and more versions of different dependencies.

The 2nd revision uses pytest to run an async unit test, and it installs an old version of aiohttp for Python versions 3.11 and 3.8. It also tests the latest aiohttp with all Python versions, from 3.8 to 3.12.

https://paiml.com/docs/home/books/testing-in-python/chapter09-testing-matrix-tox/

this might be more useful:

[tox]
envlist = py27-release_1.1, py{35,36,37,38}-release_2.x

Please verify ASDF and its plugins are installing what you expect for your own security.

asdf plugin list all | grep 'node\|py'
asdf plugin add python https://github.com/danhper/asdf-python.git
asdf plugin add nodejs https://github.com/asdf-vm/asdf-nodejs.git # https://github.com/danhper/asdf-pytho$
asdf plugin update --all
asdf list all nodejs
asdf list all python
asdf install python 3.7.17 3.8.19 ....