arrays in python

AggieDan04 danb_83 at yahoo.com
Thu Sep 24 04:03:00 CEST 2009


On Sep 23, 3:02 pm, Simon Forman <sajmik... at gmail.com> wrote:
> On Wed, Sep 23, 2009 at 1:14 PM, Rudolf <yellowblueyel... at gmail.com> wrote:
> > Can someone tell me how to allocate single and multidimensional arrays
> > in python. I looked online and it says to do the following x =
> > ['1','2','3','4']
>
> > However, I want a much larger array like a 100 elements, so I cant
> > possibly do that. I want to allocate an array and then populate it
> > using a for loop. Thanks for your help.
> > --
> >http://mail.python.org/mailman/listinfo/python-list
>
> In python they're called 'lists'.  There are C-style array objects but
> you don't want to use them unless you specifically have to.
...
> But if you do this:
>
> two_dimensional_list = [ [] for var in some_iterable]
>
> The list of lists you create thereby will contain multiple references
> to the /same/ inner list object.

No, that creates a list of distinct empty lists.  If you want multiple
references to the same inner list, it's

inner_list = []
two_dimensional_list = [inner_list for var in some_iterable]

or

two_dimensional_list = [[]] * num_copies



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