Link Review of Pylint, PyChecker and PyFlakes by Doug Hellmann

[...] All of the tools I tested found some of the errors in the sample code, but pylint was by far the most comprehensive.

[...]

For my own projects, I intend to continue looking into pylint for now. Its consistent configuration and exhaustive reporting are appealing for larger code bases such as I encounter at my day job.

[...]

see also
pylint http://www.pylint.org/ analyzes Python source code looking for bugs and signs of poor quality