Re: partitioning a string

*To*: mathgroup at smc.vnet.net*Subject*: [mg60966] Re: partitioning a string*From*: Peter Pein <petsie at dordos.net>*Date*: Wed, 5 Oct 2005 02:28:12 -0400 (EDT)*References*: <dht45r$hks$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Sara schrieb: > I have tred to partition a String and iwrote this code but its take to time to run, and it doesnt show eny result. > stringPartition[s_, n_] := Module[{}, emptyString = Mod[StringLength[s], n]; > If[emptyString != 0, empt = n - emptyString]; > str1 := " "; > str2 := ""; > For[i = 1, i <= empt, i++, str2 = str2 <> str1]; > str = s <> str2; > M = StringLength[str]; > yasList = Range[1, M/n] ; > For[i = 1, i <= M, i + n, For[j = 1, j <= M/n, j++, > yasList[[j]] = StringTake[i, j*n] > ]; > ]; > Hi Sara, 1.) even if the closing "]" from Module would be there, your function would return Null, because the nested For ends with a semicolon. 2.) empt will be uninitialized, when emptyString==0 and the first For will fail. 3.) in general: do not use variable names starting with a capital letter (M in this case). They are commonly used for function names (like N). 4.) the statement i+n should become the assignment i+=n or i=i+n. 5.) I guess StringTake[i,j] should read StringTake[str,[i,j}]? 6.) you assign values to a global variable yasList ("yet another string"?) but don't use them. b.t.w.: if you are using Module it would be a great idea to declare all local variables as local ;-) It would have been easier, to construct a list of the characters of s, partition this list and reassemble the strings. If I interpret your code correctly, you want to append spaces to your string until its length is a multiple of n. stringPartition[s_,n_]:= StringJoin @@@ Partition[Characters[s], n, n, {1, 1}, {" "}] please see the documetation for details about Partition. stringPartition["A string", 3] // InputForm gives: {"A S", "tri", "ng "} Peter