Python tracer

"""This traces python code. Add a settrace call somewhere in your program:
 
    if __name__ == '__main__':
        sys.settrace(tracer)
        main()
 
    $Id: tracer.py 234 2008-04-07 21:30:18Z noah $
"""
 
import sys, os, linecache
 
def tracer(frame, event, arg):
 
    if event == "line":
        lineno = frame.f_lineno
        filename = frame.f_globals["__file__"]
        if filename[-1] != 'y': # convert .pyc and .pyo files to .py
            filename = filename[:-1]
        line = linecache.getline(filename, lineno).rstrip().replace('\t','        ')
        print "%s : %04s : %s" % (os.path.basename(filename), lineno, line)
    return tracer