Re: complicated list selector

*To*: mathgroup at smc.vnet.net*Subject*: [mg98480] Re: complicated list selector*From*: Bill Rowe <readnews at sbcglobal.net>*Date*: Fri, 10 Apr 2009 04:58:07 -0400 (EDT)

On 4/9/09 at 5:55 AM, summertan at hotmail.com (summer) wrote: >I have the following list >data = { {11, {121, 122}}, {21, {221, 222}}, {31, {321, 322}} }; >From each sublist, I want to extract the first element and the second >element of the second sub-sub-list that is: >wanted_result={ {11, 122}, {21, 222}, {31, 322} } >I tried >data[[All, {1, {2,1}}]] >but it gives me error. >What is the right selector ? Here are three ways to achieve your desired result In[3]:= data[[All, 2]] Out[3]= {{121, 122}, {221, 222}, {321, 322}} In[4]:= Last /@ data Out[4]= {{121, 122}, {221, 222}, {321, 322}} In[5]:= data /. {a_, b_} -> b Out[5]= {{121, 122}, {221, 222}, {321, 322}}