John Arbash Meinel <[EMAIL PROTECTED]> added the comment: -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1
Raymond Hettinger wrote: > Raymond Hettinger <[EMAIL PROTECTED]> added the comment: > > John, when y=[], the update method has to create a new list iterator on > each invocation. But when y is a genexp, it is self-iterable (iow, iter > (y) will return self, not a new object). > > Also, when doing timings, it can be helpful to factor-out the attribute > lookup: > > python -m timeit -s 'x=set(range(10000)); y=[]; xu=x.update' 'xu(y)' > > __________________________________ > Tracker <[EMAIL PROTECTED]> > <http://bugs.python.org/issue2672> > __________________________________ > Sure, I wasn't surprised at the "set.update(y)" versus "set.update([])" What I was surprised at is the time for: "(i for i in [])" being about 4x longer than "set.update(i for i in [])" Anyway, the original issue is probably closed, whether we want to track into the generator stuff or not is probably a different issue. John =:-> -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFIEP4EJdeBCYSNAAMRAq+MAKC6tLjEtIBX7YgLNoYEfqjRKB4DzACglXjh cEVLEP5Hu3vpeVgVYdTbAVc= =94ja -----END PGP SIGNATURE----- __________________________________ Tracker <[EMAIL PROTECTED]> <http://bugs.python.org/issue2672> __________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
