Hello, Pyflakes 0.8 was released with some improvements. It officially supports Python 3.4 https://launchpad.net/pyflakes/+milestone/0.8 https://pypi.python.org/pypi/pyflakes In this version, the validation of the doctests is no longer active in the default configuration. The PYFLAKES_DOCTEST environment variable is used to activate them (https://bugs.launchpad.net/bugs/1223150). A new checker is added to catch return with arguments inside a generator (Python <= 3.2). The other changes are mostly bug fixes, -- Florent