[tox]
envlist = {py36,py37,py38}-pytest_{4,50,51,52,53,54,latest}

[testenv]
basepython =
    py36: python3.6
    py37: python3.7
    py38: python3.8
deps =
    pytest_4: pytest>=4.6,<5.0
    pytest_50: pytest>=5.0,<5.2
    pytest_51: pytest>=5.1,<5.2
    pytest_52: pytest>=5.2,<5.3
    pytest_53: pytest>=5.3,<5.4
    pytest_54: pytest>=5.4,<5.5
    pytest_latest: pytest
commands = pytest -rw {posargs}

[tox]
envlist = {py36,py37,py38,py39}-pytest_{4,50,51,52,53,54,latest}

[testenv]
basepython =
    py36: python3.6
    py37: python3.7
    py38: python3.8
    py39: python3.9
deps =
    pytest_4: pytest>=4.6,<5.0
    pytest_50: pytest>=5.0,<5.2
    pytest_51: pytest>=5.1,<5.2
    pytest_52: pytest>=5.2,<5.3
    pytest_53: pytest>=5.3,<5.4
    pytest_54: pytest>=5.4,<5.5
    pytest_latest: pytest
commands = pytest -rw {posargs}

Add Python 3.9 to the environments list
Add Python 3.9 to the environments list
