Using Pylint with Django

Question

Do not disable or weaken Pylint functionality by adding ignores or generated-members.
Use an actively developed Pylint plugin that understands Django.
This Pylint plugin for Django works quite well:

pip install pylint-django

and when running pylint add the following flag to the command:

--load-plugins pylint_django

Detailed blog post here.

I use the following: pylint --generated-members=objects

If you use Visual Studio Code do this:

pip install pylint-django

And add to VSC config:

"python.linting.pylintArgs": [
    "--load-plugins=pylint_django"
],

My ~/.pylintrc contains

[TYPECHECK]
generated-members=REQUEST,acl_users,aq_parent,objects,_meta,id

the last two are specifically for Django.

Note that there is a bug in PyLint 0.21.1 which needs patching to make this work.

Edit: After messing around with this a little more, I decided to hack PyLint just a tiny bit to allow me to expand the above into:

[TYPECHECK]
generated-members=REQUEST,acl_users,aq_parent,objects,_meta,id,[a-zA-Z]+_set

I simply added:

    import re
    for pattern in self.config.generated_members:
        if re.match(pattern, node.attrname):
            return

after the fix mentioned in the bug report (i.e., at line 129).

Happy days!

django-lint is a nice tool which wraps pylint with django specific settings : http://chris-lamb.co.uk/projects/django-lint/

github project: https://github.com/lamby/django-lint

Because of how pylint works (it examines the source itself, without letting Python actually execute it) it's very hard for pylint to figure out how metaclasses and complex baseclasses actually affect a class and its instances. The 'pychecker' tool is a bit better in this regard, because it does actually let Python execute the code; it imports the modules and examines the resulting objects. However, that approach has other problems, because it does actually let Python execute the code :-)

You could extend pylint to teach it about the magic Django uses, or to make it understand metaclasses or complex baseclasses better, or to just ignore such cases after detecting one or more features it doesn't quite understand. I don't think it would be particularly easy. You can also just tell pylint to not warn about these things, through special comments in the source, command-line options or a .pylintrc file.