Surfing in Kansas

This is a screencast on the Django Command Extensions project. It is one of my favorite third party apps, and it gets installed in every Django environment I work in. It provides a plethora of useful manage.py commands, and a couple other little goodies as well.

Setup

Before you get started using these things, there are a couple of packages you need to install. The first is Graphviz which is a really nice toolkit for graph visualization. The other is Werkzeug which is a little python web framework with an amazing debugger that we'll be using. There can easily be installed:

 apt-get install graphviz
 easy_install Werkzeug

Video and Download

A high-res version of the video is available here (mov 21MB)

Django Command Extensions from Eric Holscher on Vimeo.

Writeup

The website for the django extensions has a pretty good list of all of the commands that are available. Below I will just write about the way to use some of them that isn't well documented or a bit different or unclear.

As a note, for things that output something to the screen, you can redirect that output to a file really easily. For example: ./manage.py dumpscript blog > blog.py redirects the output to blog.py. The command extensions site has a list of output formats for export_emails here. Which is really useful.

The command for graphviz is /manage.py graph_models auth blog |dot -Tpng -o test.png

The output of graphviz is awesome. There are ways that you can hook this up to a url in your URLConf so that it will be regenerated whenever someone requests it (for data that changes often). That is a really nice feature for data that is changing a lot, where someone is watching over your work (school etc.).

Just to note, runserver_plus requires that you be running DEBUG = True, and that your IP Adress is in INTERNAL_IPS, look at my (screencast)[http://ericholscher.com/blog/2008/aug/28/screencast-debugging-django-error-page/] here for a full explanation of this, and more!

Things that weren't covered in the screencast include sqldiff which is still halfway working, and provides a diff against what your model and the current database look like. create_app and create_command are things that just flesh out the directory structure for a new app or management command. create_superuser creates a new supersuer for you. generate_secret_key gives you a new secret key. passwd allows you to easily change a users password. reset_db resets your current database.

Thanks for watching, and stay tuned for more screencasts (and other content too ;))