How to prevent from race conditions to share data between many process and thread in python

[mars]

I use TurboGears to do some web service. TurboGears use cherrypy. When
web browser access this site, the cherrypy will call my python
program. So my program looks like a lib. When web browser access the
site, the http server will fock a process or gerenate a thread. I need
share some data or operate some files. How can I prevent from race
conditions. Is there any way can I lock this.
Thank you in advance!