Python's profile module: <string>:1(?)
Ignore this line. It is an artifact of how the profiler is implemented. It is not telling you anything useful. Look at the "tottime" value for it: 0.000. "tottime" is the amount of time spent executing "<string>:1(?)" excluding time spent executing children of it. So, no time is spent here. "cumtime" and "percall" are large because they include time spent in children. See http://docs.python.org/library/profile.html#cProfile.run for more details.