[Tutor] array of different datatypes

[Steve Willoughby]

Dinesh B Vadhia wrote:
> Thanks Steve.  How do you sort on the second element of each list to get:
> 
> a' = [[42, 'fish'],
>         [1, 'hello']
>         [2, 'world']
>         ]

something like this would do the trick:

a_prime = sorted(a, key=(lambda i: i[1]))

sorted(a) returns a new list consisting of the elements in a
but in sorted order.  the key= parameter says how to derive the
sort key from any given element; in this case, the elements
being sorted are themselves lists, and element #1 in the sub-list
(a.k.a. "row") is the key.

> 
> 
> 
> From: Steve Willoughby 
> Sent: Monday, September 22, 2008 8:16 PM
> To: Dinesh B Vadhia 
> Cc: tutor at python.org 
> Subject: Re: [Tutor] array of different datatypes
> 
> 
> Dinesh B Vadhia wrote:
>> I have looked (honestly!) and cannot see an array structure to allow different datatypes per column.  I need a 2 column array with column 1 = an integer and column 2 = chars, and after populating the array, sort on column 2 with column 1 sorted relatively.  
> 
> 
> If by "array" you mean a regular Python list, the data type of
> every single element may be different.  So it's just how lists
> always work.
> 
> a = [[1, 'hello'],
>       [2, 'world'],
>       [42, 'fish'],
>      ]
> 
>> Thanks!
>>
>> Dinesh
>>
>>
>>
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> 
>