David Murmann wrote: > Robin Becker schrieb: > > # New attempts: > > from itertools import imap > > def flatten4(x, y): > > '''D Murman''' > > l = [] > > list(imap(l.extend, izip(x, y))) > > return l > > > > > > from Tkinter import _flatten > > def flatten5(x, y): > > '''D Murman''' > > return list(_flatten(zip(x, y))) > > well, i would really like to take credit for these, but they're > not mine ;) (credit goes to Michael Spencer). i especially like > flatten4, even if its not as fast as the phenomenally faster > flatten7. > Me too. And expand a bit on flatten4, I got this interesting result.
[EMAIL PROTECTED]:~/bonobo/psp$ python ~/lib/python2.4/timeit.py -s "import itertools; a=zip(xrange(1000),xrange(1000))" "l=len(a); li=[None]*l*2;li[::2]=range(1000); li[1::2]=range(1000)" 1000 loops, best of 3: 318 usec per loop [EMAIL PROTECTED]:~/bonobo/psp$ python ~/lib/python2.4/timeit.py -s "import itertools,psyco; a=zip(xrange(1000),xrange(1000));li=[]" "filter(li.extend,a)" 1000 loops, best of 3: 474 usec per loop Still 50% slower but it has the advantage that it works on all kinds of sequence as they can be efficiently izip() together. -- http://mail.python.org/mailman/listinfo/python-list
