idiom for initial list of lists

Oleg Broytmann phd at phd.russ.ru
Fri Sep 8 18:46:08 CEST 2000


On Fri, 8 Sep 2000, Robin Becker wrote:
> What's the correct way to initialise a list of lists I find that the
> natural [[]]*n doesn't work eg
> >>> S=[[]]*5
> >>> S
> [[], [], [], [], []]
> >>> S[0].append(1)
> >>> S
> [[1], [1], [1], [1], [1]]

   Well-known feature :)

> so I'm forced to use the rather pedantic
> S=[]
> for i in range(n): S[i].append([])

   That's the only and one correct way.

Oleg.
---- 
     Oleg Broytmann            http://phd.pp.ru/            phd at phd.pp.ru
           Programmers don't die, they just GOSUB without RETURN.





More information about the Python-list mailing list