No Python 2.0 (was Re: idiom for initial list of lists)

[Robin Becker]

In article <8peg3q$ckk$1 at panix3.panix.com>, Aahz Maruch <aahz at panix.com>
writes
....
>I think at the very least anyone proferring a 2.0 solution should
>clearly mention that 2.0 is not shipping yet.  I think it's cruel to
>hold out a carrot in front of someone and then snatch it away.

well as the rather moronic instigator of this thread I think the main
problem is that for 


>>> def six():
...     S=[[] for x in range(100000)]

>>> def one():
...     S=[]
...     for i in range(100000):
...             S.append([])

>>> def four():
...     S=map(lambda x:[],range(100000))

I get one ~= 1.49 seconds,  six ~= 1.37 seconds and four ~= 1.04 seconds

so no matter what I do it's not obvious what I should do to initialize
long lists. Comprehensions are not fast and I can only get a faster
setup by using a C method eg

>>> def five():
...     S=map(_copy_list,100000*[[]])

where five ~= 0.44 seconds

It's not at all obvious to me what the 'correct' list of list setup
idiom is.
-- 
Robin Becker