[Tutor] what's a concise way to print the first elements in a nested list

[Orri Ganel]

Danny Yoo wrote:

>On Wed, 12 Jan 2005, Orri Ganel wrote:
>
>  
>
>> >>> stuff = [[0,'sdfsd','wrtew'], [1, 'rht','erterg']]
>> >>> stuff
>>[[0, 'sdfsd', 'wrtew'], [1, 'rht', 'erterg']]
>> >>> print [stuff[i][0] for i in range(len(stuff))]
>>[0, 1]
>>    
>>
>
>
>Hi Orri,
>
>An alternative way to write this is:
>
>###
>print [row[0] for row in stuff]
>###
>
>which extracts the first element out of every "row" sublist in 'stuff'.
>
>
>Best of wishes!
>
>
>  
>

True. The only difference is the use of "for i in range(len(...))" 
instead of "for i in ...".  I suppose either works, but since Python 
only allows you to edit the elements of a sequence using the "for i in 
..." notation (and have the changes stick) inside of a list 
comprehension (and perhaps a generator, as well, I don't know), I try to 
stay away from it so I don't get confused when it doesn't work outside 
of one.

Cheers,
Orri

-- 
Email: singingxduck AT gmail DOT com
AIM: singingxduck
Programming Python for the fun of it.

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