[Tutor] Accesing "column" of a 2D list

[Ian Witham]

This looks like a job for List Comprehensions!

>>> list = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
>>> new_list = [item[1] for item in list]
>>> new_list
[2, 5, 8]
>>>

looks good?

Ian

On 8/21/07, Orest Kozyar <orest.kozyar at gmail.com> wrote:
>
> I've got a "2D" list (essentially a list of lists where all sublists are
> of
> the same length).  The sublists are polymorphic.  One "2D" list I commonly
> work with is:
>
> [ [datetime object, float, int, float],
>   [datetime object, float, int, float],
>   [datetime object, float, int, float] ]
>
> I'd like to be able to quickly accumulate the datetime column into a list.
> Is there a simple/straightforward syntax (such as list[:][0]) to do this,
> or
> do we need to use a for loop?  I expect what I have in mind is similar to
> the Python array type, except it would be polymorphic.
>
> Thanks,
> Orest
>
> _______________________________________________
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>
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