django-stubs 1.2.0

Mypy stubs for Django

pep484 stubs for Django framework

This package contains type stubs and mypy plugin to provide more precise static types and type inference for Django framework. Django uses some Python "magic" that makes having precise types for some code patterns problematic. This is why we need to accompany the stubs with mypy plugins. The final goal is to be able to get precise types for most common patterns.

Could be run on earlier versions of Django, but expect some missing imports warnings.

Installation

pip install django-stubs

Mypy compatibility

django-stubs	mypy version	django version	python version
1.2.0	0.730	2.2.x	^3.6
1.1.0	0.720	2.2.x	^3.6
0.12.x	old semantic analyzer (<0.711), dmypy support	2.1.x	^3.6

Configuration

To make mypy aware of the plugin, you need to add

[mypy]
plugins =
    mypy_django_plugin.main

in your mypy.ini or setup.cfg file.

Plugin also requires Django settings module (what you put into DJANGO_SETTINGS_MODULE variable) to be specified.

[mypy]
strict_optional = True

# This one is new:
[mypy.plugins.django-stubs]
django_settings_module = mysettings

Where mysettings is a value of DJANGO_SETTINGS_MODULE (with or without quotes)

Current implementation uses Django runtime to extract models information, so it will crash, if your installed apps models.py is not correct. For this same reason, you cannot use reveal_type inside global scope of any Python file that will be executed for django.setup().

In other words, if your manage.py runserver crashes, mypy will crash too.

This fully working typed boilerplate can serve you as an example.

Notes

Type implementation monkey-patches Django to add __class_getitem__ to the Manager class. If you would use Python3.7 and do that too in your code, you can make things like

class MyUserManager(models.Manager['MyUser']):
    pass

class MyUser(models.Model):
    objects = UserManager()

work, which should make a error messages a bit better.

Otherwise, custom type will be created in mypy, named MyUser__MyUserManager, which will rewrite base manager as models.Manager[User] to make methods like get_queryset() and others return properly typed QuerySet.

To get help

We have Gitter here: https://gitter.im/mypy-django/Lobby

If you think you have more generic typing issue, please refer to https://github.com/python/mypy and their Gitter.