multiple django projects at same url

I would like to have multiple django projects living at the same root url like this:

example.com/ # controlled by home django project  
example.com/project-2 # controlled by a separate django project  
example.com/project-开发者_Python百科3 # controlled by yet another django project  

I am already redefining the LOGIN_REDIRECT_URL, etc. as suggested by this excellent answer, but I have discovered another hurdle. I am actually using the same apps in the projects that live at example.com/project-2 and example.com/project-3, which causes some non-trivial problems for linking to content inside of a django project that have thus far been solved with seemingly hacky solutions.

For example, you can never refer to '/' in any template in either example.com/project-2 or example.com/project-3 to return to the root of the django project hosted at either of these URLs --- this will link to the home django project at example.com. To get around this, I have made a context processor that correctly prepends the root url of the project based on a custom settings.py variable SCRIPT_NAME: '' (for example.com), '/project-2' (for example.com/project-2), or '/project-3' (for example.com/project-3). This is all fine and good except that you need to do the same thing in the get_absolute_url functions. Before I knew it, I had just turned a bunch of code that was very reusable (by people other than myself) into code that was not reusable at all.

Is there a way to accomplish the same effect without having to prepend absolute URLs with the SCRIPT_NAME? Perhaps something clever with apache or mod_wsgi configuration? I am at a loss and hoping someone can help...

EDIT:

My apache configuration for example.com looks like this:

# redirect un-'/'-terminated urls to the '/'-terminated root urls
RewriteEngine On
RewriteRule /project-2$ /project-2/ [R=302,L]
RewriteRule /project-3$ /project-3/ [R=302,L]

# mod wsgi setup
WSGIScriptAlias /project-2 /srv/project2/project-2.wsgi
WSGIScriptAlias /project-3 /srv/project3/project-3.wsgi
WSGIScriptAlias / /srv/project1/project-1.wsgi

You don't show how you're serving these projects from your Apache configuration, which would have been useful. But if you define them as separate WSGIScriptAlias directives, then SCRIPT_NAME is automatically passed through for you, and Django takes it into account when reversing and creating URLs.

WSGIScriptAlias /project-2 /srv/project2/project2.wsgi
WSGIScriptAlias /project-3 /srv/project3/project3.wsgi
WSGIScriptAlias / /srv/project1/project1.wsgi