Writing/Parsing library for CSV with unknown number of columns

Question

I am trying to follow everybody's advice and use a library for my CSV writing/parsing needs. But the most recommended, FileHelpers, needs a column-mapping class. However, I just need to read write single lines of comma separated values, then parse them back later. I can't find a way to use FileHelpers or other libraries in this simple way.

For example, I make a String testInput = "\"yoyo\",\"yaya\",\"te\"\"st\""; as input, and want to parse it into a String[] with values yoyo,yaya,te"st.

Also I need to do the opposite, writing the values back to the string like this "yoyo","yaya","te"st".

Does anyone know of a library that can do this or how I can use for example FileHelpers for this?

I don't really want to do xml because of the amount of "junk" characters involved in xml fields (bandwidth/storage limitations).

score 2 · Accepted Answer · answered Apr 02 '13 at 11:16

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The CSV reader on code project should handle that; just turn off the file headers and use new StringReader(line) on a line-by-line basis.

answered Apr 02 '13 at 11:16

Marc Gravell

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Can this library also do writing arrays to csv? – David S. Apr 02 '13 at 11:20
@David not sure, but see my comment on Vyktor's post; *writing* CSV is much much easier than *reading* it – Marc Gravell Apr 02 '13 at 11:22
Thanks, I will accept this answer because `TextFieldParser` as suggested by Vyctor is apparently very slow. – David S. Apr 02 '13 at 11:26

score 2 · Answer 2 · edited May 23 '17 at 10:32

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Microsoft.VisualBasic.FileIO.TextFieldParser should be able to do the job, ReadFields method which is defined as:

Reads all fields on the current line, returns them as an array of strings, and advances the cursor to the next line containing data.

I found nice example here.

As for writing CSV, I'd use different method that I found on stackoverflow. It seems to be the simplest method that doesn't require importing 3^rd party extension.

edited May 23 '17 at 10:32

Community

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answered Apr 02 '13 at 11:17

Vyktor

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Thank you, but I also need a writer to correctly convert fields to csv, so that is only half of the solution. – David S. Apr 02 '13 at 11:19
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@David writing CSV is easier than reading it - especially if you want all the values quoted (as in this case). Replace `\"` with `\"\"` and append+prepend `\"` - job done. – Marc Gravell Apr 02 '13 at 11:20
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@David there's no CSV writer class simple enough for you... But I've added a link that I found. – Vyktor Apr 02 '13 at 11:25

Writing/Parsing library for CSV with unknown number of columns

2 Answers2