Creating a List of Empty Lists

Robin Becker robin at jessikat.fsnet.co.uk
Sat Dec 6 19:29:44 CET 2003


In article <Xns9447973F01BFduncanrcpcouk at 127.0.0.1>, Duncan Booth
<duncan at NOSPAMrcp.co.uk> writes
......
>
>The recommended way these days is usually:
>
>    a = [ [] for i in range(10) ]
>
>That still has a loop and works by appending empty lists, but at least its 
>just a single expression. Also you can incorporate the next stage of your 
>initialisation quite easily:
>
>    a = [ [b] for b in range(10) ]
>
I seem to remember the fastest way to do this was map(list,n*[[]]) from
a couple of earlier threads, but is that true in 2.3?
-- 
Robin Becker




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