[tox] envlist = py2{6,7} py3{3,4,5,6} [testenv] commands = py.test {posargs} deps: # installs the test dependencies as specified in setup.py .[tests] [testenv:py26] commands = {[testenv]commands} deps: cryptography<2.0 flake8<3.0 pytest-flake8==0.5 # installs the test dependencies as specified in setup.py .[tests] [testenv:py33] commands = {[testenv]commands} deps: cryptography<2.0 flake8<3.0 pytest-flake8==0.5 # installs the test dependencies as specified in setup.py .[tests] [flake8] ignore = E501