What I have learned about folder structure today

22 April 2011 / Technology

Easy_install (as it comes) doesn't work for Debian-based systems.

The default behaviour is to install things to /usr/local/ – this is the Gnu default – whereas the synaptic package manager installs things to /usr/. I imagine there may be a way to reconfigure the default behaviour, but I didn't get that far.

This is how I found out this rather useful piece of information. I had installed easy_install, and then used it to download all the dependencies I needed to get started with this python/Django project I was going to work on. And then – nada.

For about three hours, no matter what I did, I had this message:

File "/usr/local/lib/python2.6/dist-packages/Django-1.3-py2.6.egg/django/db/backends/mysql/base.py", line 28, in from django.db import utils ImportError: cannot import name utils

My friend who was with me, trying to get me set up to start work on the project, is a Django expert, but he uses Windows. Hey, so do I! What am I even doing using linux? (See sidebar for answer...)

We tried a lot of things. I won't go into them all here, mainly because I can't remember many of them. We tried a lot of things that people on the internet had suggested. As a last resort, we even tried to RTFM. To no avail.

After we'd given up and my friend had left, I went back to it to try and figure out what was going on. I even tried to resort to the beginner standard of adding log messages, but all the files I wanted to edit were read-only. Finally, this page offered me a glimmer of a clue.

Specifically, the question "Where are my site-packages stored?" and the answer:

python -c "from distutils.sysconfig import get_python_lib; print get_python_lib()"

Which for me, returns /usr/lib/python2.6/dist-packages

Hang on though, the error is in /usr/local/lib . . . eh?

A visit to the python2.6 folder in /usr/local confirmed that all of the stuff I needed was in there. And a call to my incredibly helpful and talented friend Joe Halliwell confirmed my growing suspicion that this was Not Correct. He explained to me the Gnu/Debian folder structure differences.

So, I backtracked. I installed everything I needed (except sorl-thumbnail, which wasn't there. However, all I need to do is find a ppa. There is probably also another way to install it correctly. By the time this is all done, I may even know what it is.)

I ran through a few errors on the way, but all of the ImportError: No module named django_extensions variety, and solved one by one, satisfyingly, by installing what I needed in the correct way.

Finally, several hours after my friend came round to work on this, I now have a new error:

File "/usr/lib/pymodules/python2.6/MySQLdb/connections.py", line 170, in __init__ super(Connection, self).__init__(*args, **kwargs2) _mysql_exceptions.OperationalError: (1045, "Access denied for user 'anna'@'localhost' (using password: NO)")

It's progress.