Django debugging with Emacs

Question

I found a lot of info about how to debug simple Python programs with Emacs. But what if I want to debug a Django application? I run the development server and I would like to so

Answer 1

Start pdb like this:

M-x pdb

Then, start the Django development server:

python manage.py runserver --noreload

Once you have the (Pdb) prompt, you need to do this:

import sys
sys.path.append('/path/to/directory/containing/views.py')

Once you've done this, you should be able to set breakpoints normally. Just navigate to the line number you want, and

C-x SPC

Answer 2

This isn't emacs specific, but you can use the Python debugger by adding the following to a Django view function:

import pdb; pdb.set_trace()

Now when you run the development server and view the page, your browser will appear to hang or load very slowly - switch over to your console, and you have access to the full debugger. You can inspect AND modify state of your application via an interactive shell - check out the Python documentation for the debugger, or this link for some Python debugging examples

---

If all you need is logging, add the following to your settings.py:

logging.basicConfig(
    level = logging.DEBUG,
    format = '%(asctime)s %(levelname)s %(message)s',
    filename = '/tmp/mylog.log',
    filemode = 'w'
)

Now you can log messages to /tmp/mylog.log by adding the following to any view function:

import logging
logging.debug("Something happened")

Answer 3

Here's something I found last night that will do exactly what you want when the program crashes:

http://code.google.com/p/django-command-extensions/

Once you install that you can run:

python manage.py runserver_plus

and you will have an interactive AJAX console on your Error page. (Obviously, be careful with the amount of access people have to this web server when running in that mode.)

GitHub: https://github.com/django-extensions/django-extensions

You can get Django Extensions by using pip or easy_install:

$ pip install django-extensions or $ easy_install django-extensions

If you want to install it from source, grab the git repository from GitHub and run setup.py:

$ git clone git://github.com/django-extensions/django-extensions.git
$ cd django-extensions
$ python setup.py install

Answer 4

I don't really know anything about it, but putting "debugging Python with emacs" into Google gave me this page about debugging twisted with emacs, so it seems to be possible.

Answer 5

Because recent versions of Emacs python mode do support 'pdbtrack' functionality by default, all you need is just set up breakpoint in your code this way:

import pdb; pdb.set_trace()

Also, you have to start your Django application devserver from within Emacs shell:

M-x shell

And then, in the shell, start the Django development server:

python ./manage.py runserver

P.S. No need for specific pdb sessions or --noreload flag. Noreload would require you to manually restart your applications and so I do not find this useful for Emacs.

Answer 6

About the general non-emacs-exclusive way, there is a very nice screencast out there you might be interested in: http://ericholscher.com/blog/2008/aug/31/using-pdb-python-debugger-django-debugging-series-/

The emacs integration described above doesn't work for me yet. It doesn't really seem to connect to the running application.

Further I consider this blog post here very interesting: http://web.archive.org/web/20101230072606/http://panela.blog-city.com/python_and_emacs_5_pdb_and_emacs.htm

cu Roman