Seeding random in django
It really depends on what you need the random number for.  Use some experimentation to find out if it makes any difference.  You should also consider that there is actually a pattern to pseudo-random numbers.  Does it make a difference to you if someone can possible guess the next random number?  If not, seed it once at the start of a session or when the server first starts up.
Seeding once at the start of the session would probably make the most sense, IMO.  This way the user will get a set of pseudo-random numbers throughout their session.  If you seed every time a page is served, they aren't guaranteed this.
In a view in django I use random.random(). How often do I have to call random.seed()?
One time for every request?
One time for every season?
One time while the webserver is running?