Jython calls Java modules and C language modules that can be called from Python. What if Python / Jython needs to call some modules in Java and some of them in C, any solution?
Jython partially supports ctypes in recent builds, so you should check if there is enough current support for your needs.
If not, you can go with JNA, http://www.flester.com/blog/2009/02/21/java-jna-jythonjruby-the-sweet-spot