Re: metacharacters as record separators

*To*: mathgroup at smc.vnet.net*Subject*: [mg26935] Re: [mg26881] metacharacters as record separators*From*: Tomas Garza <tgarza01 at prodigy.net.mx>*Date*: Fri, 26 Jan 2001 23:30:11 -0500 (EST)*References*: <200101260627.BAA18724@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

I think it would be relatively easier to perform the separation of data once you have read your records with ReadList. This way you're already inside Mathematica and things become smoother. Suppose you have a file of ordinary words which you read into your notebook with ReadList: In[1]:= originalList = ReadList["testwords.txt", Word] Out[1]= {"Those", "friends", "thou", "hast", "\",\"", "and", "their", "adoption", \ "tried", "\",\"", "grapple", "them", "unto", "thy", "soul", "with", "hoops", \ "of", "steel"} Now suppose that you wish to separate your original records using, say, the letter "h" as record separator: In[2]:= r2 = Flatten[Characters /@ originalList] Out[2]= {"T", "h", "o", "s", "e", "f", "r", "i", "e", "n", "d", "s", "t", "h", "o", \ "u", "h", "a", "s", "t", "\"", ",", "\"", "a", "n", "d", "t", "h", "e", "i", \ "r", "a", "d", "o", "p", "t", "i", "o", "n", "t", "r", "i", "e", "d", "\"", \ ",", "\"", "g", "r", "a", "p", "p", "l", "e", "t", "h", "e", "m", "u", "n", \ "t", "o", "t", "h", "y", "s", "o", "u", "l", "w", "i", "t", "h", "h", "o", \ "o", "p", "s", "o", "f", "s", "t", "e", "e", "l"} In[3]:= newList = {}; While[ r2 != {}, (ct = 0; If[r2 != {}, Scan[If[# != "h", ct += 1, Return[]] &, r2]; AppendTo[newList, Take[r2, ct]]; r2 = If[Length[r2] >= ct + 1, Drop[r2, ct + 1], r2 = {}]])] In[4]:= StringJoin /@ newList Out[4]= {"T", "osefriendst", "ou", "ast\",\"andt", "eiradoptiontried\",\"grapplet", \ "emuntot", "ysoulwit", "", "oopsofsteel"} I'm sure something more straightforward exists, but this is what came to my mind first. Tomas Garza Mexico City ----- Original Message ----- From: "Aaron E. Hirsh" <aehirsh at leland.stanford.edu> To: mathgroup at smc.vnet.net Subject: [mg26935] [mg26881] metacharacters as record separators > Is it possible to use metacharacters as part of record separators in > ReadList? For example, can one separate data at each occurrence of a > number, or at each occurrence of a character other than an uppercase > letter? > > Many Thanks, > > Aaron Hirsh > -- > > > > Aaron E. Hirsh > Center for Computational Genetics and Biological Modeling > Stanford University > tel. (650) 723-4952 > fax (650) 725-0180 >

**References**:**metacharacters as record separators***From:*"Aaron E. Hirsh" <aehirsh@leland.stanford.edu>