Vb.net parse csv file quotes

This should mean that the quote is in the middle of a string. In this case, instead of doing a direct replacement, I am using the function ReplaceQuotes to handle that for me. The reason I am using this is because I needed a little extra logic to detect whether it was at the beginning of a line. If I would have spent even more time on it, I am sure I could have tweaked the RegEx to take into consideration the beginning of the line using MultiLine, etc but when I tried it quickly, it didn't seem to work at all.

Real quick!! RegEx to exclude first and last quote would be? Of course, you need to use RegexOptions. That way there is no need for evaluator function. My code replaces undesired double quotes with single quotes. What produced these files?

It's not unlikely that there's a matching driver based on the requirements of the source application. Your problem with CSVReader is that the quote in the third record isn't escaped with another quote aka double quoting.

If you don't escape them, then how would you expect to handle ", in the middle of a text field? I did end up having to work with files with different delimiters but the quote characters inside a text value weren't escaped and I ended up writing my own custom parser.

I do not know if this was absolutely necessary or not. The logic of this custom approach is: Read through file 1 line at a time, split each line on the comma, remove the first and last character removing the outer quotes but not affecting any inside quotes , then adding the data to your generic list. It's short and very easy to read and work with. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow.

Learn more. Parse Delimited CSV in. NET Ask Question. Asked 12 years, 9 months ago. Active 4 years, 1 month ago. Viewed 80k times. Improve this question. It would help to have properly formatted CSV files to start with. Double quotes within a quoted string are supposed to be escaped by doubling. So "8" Tray of Food" is not allowed in the format.

This way, a string like hi","there can exist. Escaped and quoted, it becomes "hi"",""there". Without the doubling, it becomes "hi","there" which looks like two strings.

I agree with both of the comments above, but unfortunately, I don't have control over how the file is exported. But in the case that you do need the multiline capability, the TextFieldParser is obviously not the right tool for the task. Life Saver! And Life Changing! Thanks for showing me the light. I will never manually parse another CSV file again! Excellent post! Works great converted to VB.. Thanks, it works. Well, actually I never tested new lines within the quotes myself.

Writing a good csv parser that covers all cases is obviously non-trivial. It is obviously a very good way to parse flat files, unless you need better performance. It takes almost 9 times as much time as using StreamReader. Define the TextField type and delimiter. The following code defines the TextFieldType property as Delimited and the delimiter as ",".

Loop through the fields in the file. If any lines are corrupt, report an error and continue parsing. The following code loops through the file, displaying each field in turn and reporting any fields that are formatted incorrectly.

A row cannot be parsed using the specified format MalformedLineException. Parse a CSV File. You say the module is passed a IO. It sounds as though you have a half implemented solution. So you have an option of modifying existing streamreader code to deal with CSV and obviously you have encountered and issue with embedded comma's or change the implementation to use something explicitly designed for the purpose.

I'd probably choose the 2nd as once it processed it will be simply a collection type containing the individual fields. StreamReader is a valid overload. So it will work with my existing structure. TextFieldParser does not parse the following. I get a MalformedLineException. Any ideas how to fix it? I want to allow embedded quotes and thought the three quotes was pretty standard for an embedded single quote.

Below is the input and what I would like for output. You might want to consider using some other character to split each line into your required parts. The class that it is defined in doesn't matter. It takes a string, so as long as your IO Stream Reader can get the file text as a string, then you can use the parser. First I have not control over anything. It is a mature application that is used by 80 or so clients. I am doing support on a single issue where embedded commas are not parsing corectly on a csv, comma delimited, sometimes quoted file.

These are 4 valid customer names that I need to parse. For several reasons TextFieldParser is no longer looking like a good option for me. TextFieldParser throws an exception on a malformed file, I know that I could handle but the way the code is working I would have to move too much stuff around and there is no way to recreate the original line. So thinking more about writing something or using something that someone else has already written.