On 23 August 2018 at 17:31, Benedikt Ritter <brit...@apache.org> wrote: > Hi, > > Am Do., 23. Aug. 2018 um 12:11 Uhr schrieb sebb <seb...@gmail.com>: > >> On 23 August 2018 at 07:10, Benedikt Ritter <brit...@apache.org> wrote: >> > Hey sebb, >> > >> > Am Do., 23. Aug. 2018 um 01:23 Uhr schrieb sebb <seb...@gmail.com>: >> > >> >> On 23 August 2018 at 00:01, Bruno P. Kinoshita >> >> <brunodepau...@yahoo.com.br.invalid> wrote: >> >> > >> >> >>Maybe I'm just not getting it, but it feels pretty messed up :-) >> >> > >> >> > >> >> > Mutual feeling, and +1 for consistency. From what I understood, users >> >> should be able to parse these crazy CVS's, but if they tried to >> re-create >> >> them, with comments, then they wouldn't be able to avoid the >> >> println/newline (so it wouldn't be parseable later with the same >> reader). >> >> > >> >> > >> >> > We probably need a ticket for it to aggregate the discussion and >> maybe a >> >> possible solution. >> >> >> >> I'm wondering whether we need to be as flexible when *creating* the CSV >> >> files. >> >> >> >> "Be liberal in what you accept, and conservative in what you send" (Jon >> >> Postel) >> >> >> >> In this case send == create, as it might be sent to other less liberal >> >> readers. >> >> >> >> I don't have a problem with the output being less flexible, so long as >> >> it is sufficiently flexible (which I think it likely is already). >> >> >> >> I don't think consistency is necessary - or even desirable - here. >> >> >> > >> > okay, but wouldn't you expect that you can use a CSVFormat instance to >> read >> > a file that you created with it? This is currently not the case. >> >> Sorry, I misread the problem. >> >> Yes, it should be able to read what it writes. >> >> So the issue remains: should the reader be able to parse the unusual >> format, or should the writer not be able to create it? >> >> I don't have a particular view on that, except that allowing LF and >> CRLF only seems too restricting. >> We should allow at least CR alone. I don't know whether there are any >> other reasonable separators. >> > > As Bruno pointed out, there seem to be formats that have record separator > that are not new lines. So maybe CSVPrinter.printComment(String) should not > scan for CR and LF but for the record separator. >
Makes sense. >> >> Perhaps we could just document the method to warn that using anything >> other than CR, LF or CRLF will produce an output file that is not >> parseable? >> > > That sounds like a good approach. But how would you implement that? You > probably don't want to introduce a dependency on a logging framework just > for that, do you? I meant: add a warning to the documentation. > Regards, > Benedikt > > >> >> > Regards, >> > Benedikt >> > >> > >> >> >> >> > Cheers >> >> > >> >> > ________________________________ >> >> > From: Benedikt Ritter <brit...@apache.org> >> >> > To: Commons Developers List <dev@commons.apache.org>; >> >> brunodepau...@yahoo.com.br >> >> > Sent: Thursday, 23 August 2018 7:10 AM >> >> > Subject: Re: [CSV] Inconsistent record separator behavior >> >> > >> >> > >> >> > >> >> > Hi Bruno, >> >> > >> >> > Am Mi., 22. Aug. 2018 um 15:10 Uhr schrieb Bruno P. Kinoshita >> >> > <brunodepau...@yahoo.com.br.invalid>: >> >> > >> >> >> Hi, >> >> >> >> >> >> >> >> >> Will try to look at the code and give a better answer during the >> >> weekend. >> >> >> But risking a silly question, would it mean that users are not able >> to >> >> >> parse a CSV unless each CSV row is separated by LF or CRLF? >> >> > >> >> > >> >> > Yes. >> >> > >> >> > >> >> >> I remember getting a CSV in a government website some time ago that >> was >> >> >> formatted in a very strange way, and if I remember well it was a >> small >> >> >> file, but without LF or CRLF. I think it was using | to separate the >> >> rows, >> >> >> and , for columns. >> >> >> >> >> > >> >> > I didn't know that there are formats that don't use a new line as line >> >> > separator. >> >> > >> >> > >> >> >> >> >> >> >> >> >> Quick search returned at least another person with similar issue >> >> >> >> >> >> https://stackoverflow.com/questions/29903202/how-to-read-csv-on-python-with-newline-separator >> >> >> >> >> >> >> >> >> Not sure if I understood the problem well, but in case it makes >> sense... >> >> >> my suggestion would be to perhaps confirm if we could change >> >> >> CSVPrinter.printComment to accept other characters for line ending? >> >> >> >> >> > >> >> > The inconsistency I'm seeing is, that we an the one hand accept any >> >> > character sequence as a record separator. Comments in a way a like >> >> special >> >> > records to me. But our implementation seems to put them on a new >> "line" >> >> > using the println() method. The println() method in turn uses the >> record >> >> > seperator to start a new record. So it's not necessarily a new line. >> >> > Nevertheless while processing a comment, we look out for CR and LF and >> >> then >> >> > we call println() again. Maybe I'm just not getting it, but it feels >> >> pretty >> >> > messed up :-) >> >> > >> >> > Regards, >> >> > Benedikt >> >> > >> >> > >> >> > >> >> >> >> >> >> >> >> >> Thanks! >> >> >> >> >> >> Bruno >> >> >> >> >> >> >> >> >> ________________________________ >> >> >> From: Benedikt Ritter <brit...@apache.org> >> >> >> To: Commons Developers List <dev@commons.apache.org> >> >> >> Sent: Tuesday, 21 August 2018 7:13 PM >> >> >> Subject: [CSV] Inconsistent record separator behavior >> >> >> >> >> >> >> >> >> >> >> >> Hi, >> >> >> >> >> >> >> >> >> we have this strange handling of record separator / line endings in >> CSV: >> >> >> >> >> >> >> >> >> Users can use what ever character sequence they like as a record >> >> separator. >> >> >> >> >> >> I could for example use the ! character to mark the end of a record. >> >> >> >> >> >> Then we have CSVPrinter.printComment(String). This inserts comments >> >> into a >> >> >> >> >> >> CSV output. It detects CRLF and call println() on the CSVFormat, >> which >> >> in >> >> >> >> >> >> turn uses the record separator to indicate a new record... >> >> >> >> >> >> >> >> >> So now I'm thinking: Does it make sense to use anything else but LF >> or >> >> CRLF >> >> >> >> >> >> as record separator? Maybe we should deprecate >> >> >> >> >> >> CSVFormat.recordSeparator(String) and introduce a LineEnding enum >> where >> >> >> >> >> >> users can choose between LF and CRLF. This way we can make the >> behavior >> >> >> >> >> >> between parsing and printing consistent. >> >> >> >> >> >> >> >> >> Thoughts? >> >> >> >> >> >> Benedikt >> >> >> >> >> >> --------------------------------------------------------------------- >> >> >> To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org >> >> >> For additional commands, e-mail: dev-h...@commons.apache.org >> >> > >> >> >> >> >> >> >> >> > >> >> > --------------------------------------------------------------------- >> >> > To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org >> >> > For additional commands, e-mail: dev-h...@commons.apache.org >> >> > >> >> >> >> --------------------------------------------------------------------- >> >> To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org >> >> For additional commands, e-mail: dev-h...@commons.apache.org >> >> >> >> >> >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org >> For additional commands, e-mail: dev-h...@commons.apache.org >> >> --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org For additional commands, e-mail: dev-h...@commons.apache.org
