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()

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 ....