Re: Sorting nested lists with strings
- To: mathgroup at smc.vnet.net
- Subject: [mg116302] Re: Sorting nested lists with strings
- From: Bill Rowe <readnews at sbcglobal.net>
- Date: Thu, 10 Feb 2011 05:23:11 -0500 (EST)
On 2/9/11 at 2:09 AM, kgodelNOSPAM at liberoNOSPAM.it (Paperorbifold)
wrote:
>I've a nested list of this kind:
>list={{"Paul",23},{"Amanda",55},{"Carl",32},...} Suppose I want to
>perform an alphabetic sort on the first element. Which is the
>condition I've to write in Sort[list,...]? Actually Sort[list]
>automatically operates on the second element.
What??? Not here
In[1]:= list = {{"Paul", 23}, {"Amanda", 55}, {"Carl", 32}};
In[2]:= Sort[list]
Out[2]= {{"Amanda", 55}, {"Carl", 32}, {"Paul", 23}}
But I can sort by the second element by either using a pure
function or by using SortBy
In[3]:= Sort[list, Last@#1 < Last@#2 &]
Out[3]= {{"Paul", 23}, {"Carl", 32}, {"Amanda", 55}}
In[4]:= SortBy[list, Last]
Out[4]= {{"Paul", 23}, {"Carl", 32}, {"Amanda", 55}}