Sequence of empty lists

[JP. Baker]

I give up (and have prepared myself for replies telling
me which search strings to use on Google etc)!

How *should* I create a sequence of N empty lists (buckets)?

I obviously can't use

a = [[]]*N

and I have found various solutions and am currently using

a = map(lambda x: [], range(N))

but can't help feeling that I have missed something obvious.

nhoJ
--
John P Baker

[Diez B. Roggisch]

Re: Sequence of empty lists


seq = [[] for i in xrange(10)]

--
Regards,

Diez B. Roggisch

[Peter Hansen]

Re: Sequence of empty lists

Diez B. Roggisch wrote:[color=blue]
> seq = [[] for i in xrange(10)][/color]

And the reason you need that approach is given in the FAQ:

http://www.python.org/doc/faq/programming.html#how-do-i-create-a-multidimensional-list

It's a very good idea to read the entire FAQ as soon as you've gotten
past the very basic Python level, so that you can save yourself
and others a lot of time stumbling over the traditional problems
that everyone goes through. You'll learn a lot of useful things
in the process.

-Peter

[Paul Rubin]

Re: Sequence of empty lists

ccjpb@shark.cse .bris.ac.uk (JP. Baker) writes:[color=blue]
> How *should* I create a sequence of N empty lists (buckets)?[/color]

a = [[] for i in xrange(N)]