Re: Re: Reading csv with ;

*To*: mathgroup at smc.vnet.net*Subject*: [mg99533] Re: [mg99493] Re: Reading csv with ;*From*: George Woodrow III <georgevw3 at mac.com>*Date*: Thu, 7 May 2009 06:36:57 -0400 (EDT)*References*: <gtp1h5$k58$1@smc.vnet.net> <200905060929.FAA02205@smc.vnet.net>

A better way to read in text data is to use ReadList[] instead of Import[]. It is better documented as well. I made a test file: 1;2;3;4;5;6 7;8;9;10;11;12 FilePrint["tempList.txt"] 1;2;3;4;5;6 7;8;9;10;11;12 The lines are terminated with carriage returns, and there is an extra carriage return at the end. Here is what happens with Import[]: In[33]:= Import["tempList.txt", "Table", "FieldSeparators" -> ";"] Out[33]= {{1, 2, 3, 4, 5, 6}, {7, 8, 9, 10, 11, 12}, {}} Here is what happens with ReadList[]: In[24]:= ReadList["tempList.txt", Word, WordSeparators -> ";"] Out[24]= {"1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12"} You can preserve the records like this: In[38]:= ReadList["tempList.txt", {Word, Word, Word, Word, Word, Word}, WordSeparators -> ";"] Out[38]= {{"1", "2", "3", "4", "5", "6"}, {"7", "8", "9", "10", "11", "12"}} You can convert the strings to numbers by wrapping ToExpression[] around it. In[39]:= ToExpression[ ReadList["tempList.txt", {Word, Word, Word, Word, Word, Word}, WordSeparators -> ";"]] Out[39]= {{1, 2, 3, 4, 5, 6}, {7, 8, 9, 10, 11, 12}} Note that in the last three examples, the extra carriage return is lost. Here is a final way to do it: In[52]:= Partition[ToExpression[StringSplit[Import["tempList.txt"], {";", "\n"}]], 6] Out[52]= {{1, 2, 3, 4, 5, 6}, {7, 8, 9, 10, 11, 12}} Using Import[] is more elegant here. It is too bad that "FieldSeparators" is so poorly documented. As a final note, just incase someone from Wolfram is paying attention: ? *Separator* System` NumberSeparator VerticalSeparator $PathnameSeparator RecordSeparators WordSeparators=09 I think that this command should at least list FieldSeparators. It does not. george woodrow On May 6, 2009, at 5:29 AM, dh wrote: > > > Hi Dennis, > > assume we have a file: > > 1;2 > > 3;4 > > we can read this by e.g.: > > > > Import["d:/tmp/t.txt", "Table", "FieldSeparators" -> {";"}] > > > > The magic word is "FieldSeparators". > > Daniel > > > > Dennis wrote: > >> I'm trying to read a csv with mathematica > >> > >> Now the problem is that my system settings are at ";" as seperator >> instead of more traditional ",". So the it effectively looks like >> 1;1;1;1 instead of 1,1,1,1 > >> > >> Normally this makes not difference as in most software you can >> choose the delimiter/seperator before reading a file, so you pick >> =93separator = ;=94 or whatever. > >> > >> With mathematica however I have so far been unable to do this. Now >> the question of course: how so I change the seperator with >> mathematica? > >> > >> Because quite a few files have a =93;=94 separator I would like to find >> a solution within mathematica instead of changing the system >> settings. > >> > >> Cheers, > >> > >> Dennis > >> > > >

**References**:**Re: Reading csv with ;***From:*dh <dh@metrohm.com>