Question

我正在尝试创建一个正则表达式来获取下面字符串的输出，以4个逗号分隔值的集合。我尝试了一些东西，但它只选择每个逗号分隔值。我不知道如何获得所需的输出。

我试过的正则表达式：

".*?"(?=,|$)

数据：

"T","Success","2","2","T","Success","6458960","1","F,"You do not have sufficient credit.","6458962","1"

渴望出来：

"T","Success","2","2"  
"T","Success","6458960","1"  
"F,"You do not have sufficient credit.","6458962","1"

更新：＆＃34; F也是双引号，这是一个错字，抱歉！＆＃34;

＆＃34; T＆＃34;＆＃34;成功＆＃34;＆＃34; 2＆＃34;＆＃34; 2＆＃34;＆＃34; T＆＃34;＆＃ 34;成功＆＃34;，＆＃34; 6458960＆＃34;，＆＃34; 1＆＃34;，＆＃34; F＆＃34;，＆＃34;您没有足够的信用。＆＃34;，＆＃34; 6458962＆＃34;＆＃34; 1＆＃34;

Answer 1

您只需要String.Split并且：

string[] fields = str.Split(',');
for (int i = 0; i < fields.Length; i += 4)
    Console.WriteLine(string.Join(",", fields.Skip(i).Take(4)));

输出：

"T","Success","2","2"
"T","Success","6458960","1"
"F,"You do not have sufficient credit.","6458962","1"

这假设这不是真正的csv数据。否则我建议使用真实的CSV parser that supports quoting characters。但似乎它们无论如何都被打破了（,"1","F,.，所以F没有用引号括起来。）

Answer 2

您可以使用以下正则表达式，但前提是F也在括号中：

((?:".+",){3}(?:".+"))

这导致：

比赛1 1. [0-21] "T","Success","2","2"

比赛2 1. [22-49] "T","Success","6458960","1"

比赛3 1. [50-104] "F","You do not have sufficient credit.","6458962","1"

Regex Demo

如果数据确实是这种不一致的形式，您必须手动解析它或使用或条件修改正则表达式。

Answer 3

((?:"[^"]*"|[^,"])*(?:,(?:"[^"]*"|[^,"])*){3}),?

(?:"[^"]*"|[^,"])*将匹配逗号之间的值，可选择引用。报价将转义为""。
(X(?:,X){3}),?其中X是模式＃1，将匹配四个逗号分隔值的序列，以及一个可选的尾随逗号。必须使用逗号才能正确匹配空值（,,foo,）。

如果保证值始终有引号，您可以删除|[^,"]和,?。

Answer 4

你可以试试这个正则表达式，但是正则表达式有一个问题：你需要修剪一下Comma，甚至还有更多Comma字符串，而不是4 Comma的倍数}，它也可以正常工作

string patten = @"(?<=^(?:(?:[^,]*,){4})+)";
string text = @"""T"",""Success"",""2"",""2"",""T"",""Success"",""6458960"",""1"",""F,""You do not have sufficient credit."",""6458962"",""1""";
foreach (var tmp in Regex.Split(text, patten))
{
    Console.WriteLine(tmp.TrimEnd(','));
}

Answer 5

我会避免使用正则表达式，除非你真的需要它，通常它们可能更难理解。

这里有趣的是Linq解决方案：

var data = @"""T"",""Success"",""2"",""2"",""T"",""Success"",""6458960"",""1"",""F,""You do not have sufficient credit."",""6458962"",""1""";

var res = data.Split(',')
            .Select((x ,i) => new { Pos = i / 4, Val = x })
            .GroupBy(x => x.Pos)
            .Select(g => string.Join(",", g.Select(x => x.Val)));

正则表达式提取符匹配字符串中的每第四个逗号

5 个答案: