I'm happy to change the function name, though I'll note that the traceback module does have print_tb(), format_tb() and extract_tb(). 

I'm OK with both of Victor's suggestions but personally slightly prefer traceback.clear_frames(tb).

Rationale: People who are keeping tracebacks around and want to save memory are probably using other functions from the traceback module, and the module has fairly short names (print_tb, format_exception) so I doubt they'll often do 'from traceback import clear_traceback_frames'.