"Diez B. Roggisch" <[EMAIL PROTECTED]> writes: > Paul Rudin wrote: > >> Dr Mephesto <[EMAIL PROTECTED]> writes: >> >>> Hi! >>> >>> I would like to create a pretty big list of lists; a list 3,000,000 >>> long, each entry containing 5 empty lists. My application will append >>> data each of the 5 sublists, so they will be of varying lengths (so no >>> arrays!). >>> >>> Does anyone know the most efficient way to do this? I have tried: >>> >>> list = [[[],[],[],[],[]] for _ in xrange(3000000)] >>> >>> but its not soooo fast. Is there a way to do this without looping? >> >> You can do: >> >> [[[],[],[],[],[]]] * 3000000 >> >> although I don't know if it performs any better than what you already >> have. > > You are aware that this is hugely different, because the nested lists are > references, not new instances? Thus the outcome is most probably (given the > gazillion of times people stumbled over this) not the desired one...
Err, yes sorry. I should try to avoid posting before having coffee in the mornings. -- http://mail.python.org/mailman/listinfo/python-list
