StringBuilder export csv with quotation marks at the beginning

Question

I want to write several csv lines into a csv file with StringBuilder. I enclose every field with quoation marks. If I export the file as a .txt I have excactly what I want ("Artist","Album","Track"). If I export as .csv the first field is not enclosed with quoation marks (Artist,"Album","Track"). Some test code that reproduces the issue:

static void Main(string[] args)
{
  StringBuilder csv = new StringBuilder();

  string artist = EncloseComma("Artist");
  string album = EncloseComma("Album");
  string track = EncloseComma("Track");

  string newLine = string.Format("{0},{1},{2}", artist, album, track);
  csv.AppendLine(newLine);
  File.WriteAllText("test.csv", csv.ToString());
}

private static string EncloseComma(string str)
{
  return "\"" + str + "\"";
}

`EncloseComma` is an incredibly poor name for that function. — Sam Axe, Mar 16 '17 at 20:26
Ran your test code and opened the CSV via notepad, the quotation marks are present for all three fields... — StfBln, Mar 16 '17 at 20:26
there are libraries that do this already. try using them instead of reinventing the wheel. — Selman Genç, Mar 16 '17 at 20:27
And note that that's still not a valid CSV file. You need to escape any quotes that might be in the actual data. — Servy, Mar 16 '17 at 20:27
Its unclear what "export as .txt" and "export as .csv" mean. How are the two different, in your mind and in your code? — Sam Axe, Mar 16 '17 at 20:27
What program did you use to open the .csv file? I use excel and no quotes at all, but when I use Notepad++ , all the words have quotes. Your questions is not clear — Dan Hunex, Mar 16 '17 at 20:33
@SamAxe the difference is the file ending when using File.WriteAllText — Tim Kathete Stadler, Mar 16 '17 at 20:37
@DanHunex you are right, I see all quotes in Notepad++, but in excel the first field has no quotes.. weird. — Tim Kathete Stadler, Mar 16 '17 at 20:39

tRuEsAtM · Answer 1 · 2017-03-16T22:47:20.927

1

This code worked for me:

    private static string AddDoubleQuotes(string str)
    {
        str = $"\"" + "\"" + "\"" + str + "\"" + "\"" + "\"";
        return str;
    }

Just add two more escape characters like \" in total 3.

edited Mar 16 '17 at 22:47

answered Mar 16 '17 at 21:13

tRuEsAtM

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score 1 · Accepted Answer · answered Mar 16 '17 at 22:01

While the quotes will be visible in Notepad for example, it is quite normal they don't appear in Excel or when read with another csv parser.

The quotes in a csv file are only there to enclose fields that could have a delimiter inside them (they don't even mean the field should be treated as a string, quotes could as well be around numbers containing a separator).

To have the quotes still visible after parsing, they have to be escaped with another quote, and then surrounded with quotes to have a quoted field, like this:

"""Artist""","""Album""","""Track"""

For the same reason, when generating a csv file from code, every field should be checked for delimiters and quotes and those quotes then have to be escaped with another quote.

StringBuilder export csv with quotation marks at the beginning

2 Answers2