Python static code analysis with pylint

Pylint is a python tool that checks if a module satisfies a coding standard. You can install pylint with easy_install (pylint has dependencies on logilab_common and logilab_astng, so consider download them as well in case of offline install).

easy_install pylint

Running checks is pretty easy:

user1@deby:~/devenv/trunk/src$ ../../bin/pylint greatings
No config file found, using default configuration
************* Module greatings
C:  1: Missing docstring
************* Module greatings.helloworld
C:  1: Missing docstring
C: 10:main: Missing docstring
************* Module greatings.tests
C:  1: Missing docstring
W:  4: Relative import 'test_helloworld', should be 
'greatings.tests.test_helloworld'
W:  7:suite: Redefining name 'suite' from outer scope (line 6)
C:  6:suite: Missing docstring
************* Module greatings.tests.test_helloworld
C:  1: Missing docstring
C:  4:HelloworldTestCase: Missing docstring
C:  6:HelloworldTestCase.test_say: Missing docstring
R:  6:HelloworldTestCase.test_say: Method could be a function
W: 12:suite: Redefining name 'suite' from outer scope (line 10)
C: 10:suite: Missing docstring
  ...
Global evaluation
-----------------
Your code has been rated at 5.94/10

The tool also produces a report that include:

• Statistics by type
• External dependencies
• Duplication
• Raw metrics
• Messages by category
• % errors / warnings by module
• Messages

If you want to change the default behaviour, you can define options in pylintrc file (use --rcfile option to specify a location). Here is an example.

user1@deby:~/devenv/trunk$ wget -P tools/ http://www.\
logilab.org/cgi-bin/hgwebdir.cgi/pylint/raw-file\
/df8f34aa3dd2/examples/pylintrc
user1@deby:~/devenv/trunk$ cd src/
user1@deby:~/devenv/trunk/src$ ../../bin/pylint \
--rcfile=../tools/pylintrc greatings

Read more about pylint here.