Le Wed, 16 Oct 2013 14:09:16 +0200, Antoine Pitrou <solip...@pitrou.net> a écrit : > Le Wed, 16 Oct 2013 14:01:37 +0200, > Victor Stinner <victor.stin...@gmail.com> a écrit : > > 2013/10/16 Antoine Pitrou <solip...@pitrou.net>: > > >> By the way, what are the performances of contextlib.ignore()? > > >> Exceptions can be slow in some cases. Adding something even > > >> slower would not be a good idea. > > > > > > A "try" block which succeeds is fast. > > > > Ah yes, I never reminder this fact. I try to not care too much of > > micro-optimizations :-) > > It's not so much a micro-optimization than the fact that pushing a > block on the stack is very cheap. > IIRC, what is expensive is: > - creating the exception object with the associated traceback > - matching the exception in the "exception SomeException" clause
By the way, of course this must be kept in proportion. At worse the total cost is a couple of microseconds. Still, a simplistic micro-benchmark: $ ./python -m timeit "try: pass" "except Exception: pass" 100000000 loops, best of 3: 0.0164 usec per loop $ ./python -m timeit -s "from contextlib import ignore" "with ignore(Exception): pass" 100000 loops, best of 3: 2.21 usec per loop Regards Antoine. _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
