why is __init__ module in django project loaded twice

Question

I put

print 'Hello world!'

into __init__.py in my django project. When I run ./manage.py runserver now, I get

gruszczy@gruszczy-laptop:~/Programy/project$ ./manage.py runserver
Hello world!
Hello world!
Validating models...
0 errors found

Why is __init__.py run twice? It should be loaded only once.

Answer 1

It should be loaded only once... per process. I'm guessing that manage.py forks, and that two separate processes are launched. Could you print the result of os.getpid()?

Answer 2

One simple way of finding out would be to raise an exception. Perhaps something like this in your init.py:

import os
if os.path.isfile('/tmp/once.log'):
    raise Exception
open('/tmp/once.log','w').write('first time')

Then you can inspect the traceback.