Hi everyone, I have been working on some feature of a deterministic profiler( github.com/sumerc/yappi). The feature is about getting arguments for a given set of function names. For example: you can define something like foo 1,3,arg_name and when foo function is called, profiler will simply collect the first, third from *args and a named argument arg_name from *kwargs. For Python functions I am using following approach: Please note that the code below is executing in the PyTrace_CALL event of the profiler in C side: Look co_argcount and co_varnames to determine the names of arguments and then use these names to retrieve values from f_locals. It seems to be working fine for now. My first question is: Is there a better way to do this? And for C functions, I am totally in dark. I have played with f_valuestack and retrieve some values from there but the indexes seem to change from Python version to version and also I think there is no way of getting named arguments... I have been dealing with this for a while, so there might be unclear points in my explanation. I would really appreciate if anyone can help me on a correct direction on this. Thanks, Best Regards. -- Sümer Cip