1. PyDebug: A New Application for Integrated Debugging of Python with C and Fortran Extensions Peter Stoltz Tech-X Corporation pstoltz@txcorp.com O'Reilly Open Source Convention Thursday, July 26, 2001 Python Session Tech-X Corporation 5541 Central Ave., Suite 135 Boulder, Colorado 80301 http://www.techxhome.com

2. p. 2 Overview of Tech-X Corporation We are a small company funded primarily via the federal SBIR program –we have 9 employees, 6 of them PhD physicists –we receive funding from DoE, DoD, DoEd, and (hopefully) NIH Tech-X collaborates with DoE labs and universities –we have active collaborations with LBNL, LLNL, ORNL, PPPL, Berkeley, MIT, U. of Colorado, and U.T. Austin Among our Python projects are developing a data client- server application and high-performance steering tools: –developing a CORBA-based client-server application with a Python server for magnetic fusion energy research –developing Python tools for steering Fortran 77 code in the heavy- ion fusion energy reserch (we’re heavily involved with Pyfort)

3. p. 3 We have a partial solution of the problem of simultaneously debugging Python and C/Fortran A known problem in the Python community is debugging Python code and C/Fortran extensions simultaneously: –You can use built-in Python debugger to debug native Python, but not extensions written in C/Fortran –You can run Python under gdb, but it’s awkward (e.g. you can’t restart your code easily) PyDebug, a middle-ware interpreter (written in Python, of course!), solves this problem: –Using threads, the middle-ware launches gdb (or some other debugger) while still listening to stdin –Using the cmd module, the middle-ware can filter commands from stdin and do any necessary manipulation (e.g. adding breakpoints to a PyDebug list) before issuing the command

4. p. 4 PyDebug is a middle layer between the user and gdb user stdin/stdout PyDebug gdb python cmdthreads

5. p. 5 PyDebug 0.9b is available for download To try PyDebug, please visit http://pydebug.techxhome.com

6. p. 6 Abstract