creating really big lists
Paul Rudin
paul.nospam at rudin.co.uk
Wed Sep 5 06:00:38 EDT 2007
Dr Mephesto <dnhkng at googlemail.com> 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.
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