Is there any way to check if a function is user-defined?

[Ofnuts]

For a given function you can find its source file:

import sys

sourceFile=sys.modules[function.__module__].__file__

(except for some built-in modules, but this answer the question). Then you can probably deduce if the function is locally coded by the location of the file.

[dullboy]

Okay, I explain why I asked this question. Basically I want to call settrace to list all the functions executed during the program run. But I want to list only user-defined functions executed during the program run. So I need to figure out how to differentiate user-defined functions from library functions. Hopefully I explain myself well. Thanks.