CSV中双引号值的正则表达式

Question

Given the following data, I'd like a Regex to pull out each comma-separated value. However, a double-quoted value may contain commas.

"SMITH, JOHN",1234567890,"12/20/2012,11:00",,DRSCONSULT,DR BOB - OFFICE VISIT - CONSULT,SLEEP CENTER,1234567890,,,"a, b"
"JONES, WILLIAM",1234567890,12/20/2012,12:45,,DRSCONSULT,DR BOB - OFFICE VISIT - CONSULT,SLEEP CENTER,,,,

Here's the expression that I have so far:

(?<=^|,)(?:(?:(?<=\")([^\"]*)(?=\"))|(?:(?<![\"])([^,\"]*)(?![\"])))(?=$|,)

Debuggex Demo

The double-quoted values are not being matched. What am I doing wrong? (This Regex is passed into pre-existing code - I cannot rewrite the system.)

Answer 1

How about:

(?<=^|,)(("[^"]*")|([^,]*))(?=$|,)

Debuggex Demo

The first alternative is:

("[^"]*")

Match a " followed by anything that's not a " followed by a "

The second alternative is just:

([^,]*)

Match anything that isn't a ,

Answer 2

This pattern should work:

(\w+\,\s\w+|[\d\/]*\,\d+\:\d*|[\w\d\:\s\-]+)

example:

http://regex101.com/r/rI8nS1

When using the pattern in C# you might need to escape it llke:

Match match = Regex.Match(searchText, "(?m)(?x)(\\w+\\,\\s\\w+|[\\d\\/]*\\,\\d+\\:\\d*|[\\w\\d\\:\\s\\-]+)"); 
    if (match.Success) {...}

Answer 3

Here's the code which I use for coping with quote-aware CSVs

//regex to translate a CSV
readonly Regex csvParser = new Regex( "(?:^|,)(\\\"(?:[^\\\"]+|\\\"\\\")*\\\"|[^,]*)", RegexOptions.Compiled);

//given a row from the csv file, loop through returning an array of column values
private IEnumerable<string> ProcessCsvRow(string row)
{
    MatchCollection results = csvParser.Matches(row);
    foreach (Match match in results)
    {
        foreach (Capture capture in match.Captures)
        {
            yield return (capture.Value ?? string.Empty).TrimStart(",").Trim('"', ' ');
        }
    }
}