Re: List Partition

*To*: mathgroup at smc.vnet.net*Subject*: [mg53899] Re: [mg53895] List Partition*From*: János <janos.lobb at yale.edu>*Date*: Wed, 2 Feb 2005 18:10:40 -0500 (EST)*References*: <200502021125.GAA29007@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

On Feb 2, 2005, at 6:25 AM, zak wrote: > what could i do to partition the list: > a={cat,E,in,the,hat,E,okay,fine,E} > into > a={{cat},{{in},{the},{hat}},{{okay},{fine}}} > > ie: every word in a sublist , and E determine the end of a sentence > (a bigger list). > zak > Here is a "procedural" solution. In[49]:= zaklst = {"cat", "E", "in", "the", "hat", "E", "okay", "fine", "E"} Out[49]= {"cat", "E", "in", "the", "hat", "E", "okay", "fine", "E"} In[60]:= zakprt = First[Last[ Reap[While[zaklst =!= {}, current = Take[zaklst, {1, First[Flatten[ Position[zaklst, "E"]]] - 1}]; zaklst = Take[zaklst, {First[Flatten[ Position[zaklst, "E"]]] + 1, Length[zaklst]}]; Sow[current]; ]]]] Out[60]= {{"cat"}, {"in", "the", "hat"}, {"okay", "fine"}} Here is a "functional" one: In[79]:= (Rest[Most[Take[Join[{"E"}, zaklst], #1]]] & ) /@ Partition[Flatten[ Position[Join[{"E"}, zaklst], "E"]], 2, 1] Out[79]= {{"cat"}, {"in", "the", "hat"}, {"okay", "fine"}} I learned all these techniques from the members of this list. János ---------------------------------------------- Trying to argue with a politician is like lifting up the head of a corpse. (S. Lem: His Master Voice)

**References**:**List Partition***From:*zak <chocolatez@gmail.com>