[mod_python] can I create files or directories?

I have mod_python set up and have some test sites up and running on my
server.  I'm having problems using os.mkdir and opening files with 'w'
permissions.  Are there additional security measures being taken by
the mod_python apache module to not allow writing to files/or adding
dirs/files to the server?

My apache server is running with the user apache and group apache and
the files and directories that I want to write to are writable by the
apache user so I just wanted to make sure that the module wasn't
stopping me from doing this.

Cheers
Josh