[tox] envlist = py26, py27, py33, py34, py35 [testenv] setenv = PYTHONPATH = {toxinidir}:{toxinidir}/py-polymorphic-loader deps = -r{toxinidir}/requirements_dev.txt commands = py.test --basetemp={envtmpdir} ; If you want to make tox run the tests with the same versions, create a ; requirements.txt with the pinned versions and uncomment the following lines: ; deps = ; -r{toxinidir}/requirements.txt