Skip to main content

How To use Sphinx Autodoc on ReadTheDocs with a Django application

Sphinx is awesome for writing documentation. ReadTheDocs is awesome for hosting it. Autodocs are great for covering your entire API easily. Django is a great framework that makes my job easier.


Between these four things is an interaction that only brought me pain, however. I'm here to help the next dev avoid this.


Autodocs works by importing your modules and walking over the classes and functions to build documentation out of the existing docstrings. It can be used to generate complete API docs quickly and keep them in sync with the libraries existing docstrings, so you won't get conflicts between your docs and your code. Fantastic.

This creates a problem when used with Django applications, where many things cannot be imported unless a valid settings module can be found. This can prevent a hurdle in some situations, and requires a little boilerplate to get working properly with Sphinx. It require a little extra to get working on ReadTheDocs. What makes this particularly hard to figure out, is the environment running on their servers is not the same as your own, and you have only terse error reports to guess about.

Here is the snippet you need to add into the conf.py of your docs/ to tell Sphinx how to load a settings.py.

import sys, os

sys.path.append(os.path.dirname(__file__))
import django 

os.environ.setdefault("DJANGO_SETTINGS_MODULE", "settings")
if django.VERSION < (1, 4):
    from django.core.management import setup_environ

    settings = __import__(os.environ["DJANGO_SETTINGS_MODULE"])
    setup_environ(settings)


and a simple settings.py is all you need sitting beside that.

# Django settings for docs project.
# import source code dir
import os
import sys
sys.path.insert(0, os.getcwd())
sys.path.insert(0, os.path.join(os.getcwd(), os.pardir))

SITE_ID = 303
DEBUG = True
TEMPLATE_DEBUG = DEBUG

DATABASES = {"default": {

    "NAME": ":memory:",
    "ENGINE": "django.db.backends.sqlite3",
    "USER": '',
    "PASSWORD": '',
    "PORT": '',

}}

INSTALLED_APPS = (
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.sites',
    'YOUR_APP_HERE', # This is where you put your app
)



And you should be good to go!

Comments

Anentropic said…
I'm not quite clear from this... do you propose a structure like:

mydjangoproj/
mydjangoproj/settings.py
mydjangoproj/myapp/
mydjangoproj/docs/conf.py
mydjangoproj/docs/settings.py

i.e. a separate settings.py just for your docs/ dir that points up at the main django root?

I guess you still need to go through and add ..automodule directives to the rst index for all your INSTALLED_APPS ?

Sorry for dumb questions, first time I've used Sphinx...
Calvin Spealman said…
Anentropic,

Yes, you've got it right.

Usually a project has lots of settings anyway. Local dev settings, staging, production, different settings for celery workers, etc. Docs is just one more context you need some settings for.
Alex Little said…
Thanks for posting this - it really helped me out - I was struggling to resolve the errors about Django settings in the ReadTheDocs build output.
Alex

Popular posts from this blog

CARDIAC: The Cardboard Computer

I am just so excited about this. CARDIAC. The Cardboard Computer. How cool is that? This piece of history is amazing and better than that: it is extremely accessible. This fantastic design was built in 1969 by David Hagelbarger at Bell Labs to explain what computers were to those who would otherwise have no exposure to them. Miraculously, the CARDIAC (CARDboard Interactive Aid to Computation) was able to actually function as a slow and rudimentary computer.  One of the most fascinating aspects of this gem is that at the time of its publication the scope it was able to demonstrate was actually useful in explaining what a computer was. Could you imagine trying to explain computers today with anything close to the CARDIAC? It had 100 memory locations and only ten instructions. The memory held signed 3-digit numbers (-999 through 999) and instructions could be encoded such that the first digit was the instruction and the second two digits were the address of memory to operate on

The Range of Content on Planet Python

I've gotten a number of requests lately to contribute only Python related material to the Planet Python feeds and to be honest these requests have both surprised and insulted me, but they've continued. I am pretty sure they've come from a very small number of people, but they have become consistent. This is probably because of my current habit of writing about NaNoWriMo every day and those who aren't interested not looking forward to having the rest of the month reading about my novel. Planet Python will be getting a feed of only relevant posts in the future, but I'm going to be honest: I am kind of upset about it. I don't care if anyone thinks it is unreasonable of me to be upset about it, because the truth is Planet Python means something to me. It was probably the first thing I did that I considered "being part of the community" when I submitted my meager RSS feed to be added some seven years ago. My blog and my name on the list of authors at Plan

Pythonic Defined

Introduction Losing is Good Strings Dictionaries Conclusion Introduction Veterans and novices alike of Python will hear the term "pythonic" thrown around, and even a number of the veterans don't know what it means. There are times I do not know what it means, but that doesn't mean I can define a pretty good idea of what "pythonic" really means. Now, it has been defined at times as being whatever the BDFL decides, but we'll pull that out of the picture. I want to talk about what the word means for us today, and how it applied to what we do in the real world. Languages have their strengths and their idioms (ways of doing things), and when you exploit those you embrace the heart of that language. You can often tell when a programmer writing in one language is actually more comfortable with another, because the code they right is telltale of the other language. Java developers are notorious for writing Java in every language they get their hands on. Ho