正则表达式拆分 CSV [英] Regex to split a CSV

问题描述

我知道这个(或类似的)已经被问过很多次了，但是在尝试了很多可能性之后，我一直没能找到一个 100% 有效的正则表达式.

我有一个 CSV 文件，我试图将它拆分成一个数组，但遇到两个问题:引号引起来的逗号和空元素.

CSV 看起来像:

123,2.99,AMO024,Title,"描述，更多信息",,123987564

我尝试使用的正则表达式是:

thisLine.split(/,(?=(?:[^"]*"[^"]*")*(?![^"]*"))/)

唯一的问题是在我的输出数组中，第 5 个元素显示为 123987564 而不是空字符串.

解决方案

说明

我认为简单地执行匹配并处理所有找到的匹配会更容易，而不是使用拆分.

这个表达式将:

• 用逗号分隔您的示例文本
• 将处理空值
• 将忽略双引号逗号，前提是双引号不嵌套
• 从返回值中去除分隔逗号
• 从返回值中修剪周围的引号

正则表达式:(?:^|,)(?=[^"]|(")?)"?((?(1)[^"]*|[^,"]*))"?(?=,|$)

示例

示例文本

123,2.99,AMO024,Title,"描述，更多信息",,123987564

使用非 java 表达式的 ASP 示例

设置正则表达式 = 新正则表达式regEx.Global = 真regEx.IgnoreCase = TrueregEx.MultiLine = Truesourcestring = "你的源字符串"regEx.Pattern = "(?:^|,)(?=[^""]|("")?)""?((?(1)[^""]*|[^,""]*))""?(?=,|$)"设置匹配 = regEx.Execute(sourcestring)对于 z = 0 到 Matches.Count-1结果 = 结果 &"匹配(" & z & ") = " &chr(34) &Server.HTMLEncode(Matches(z)) &chr(34) &铬(13)对于 zz = 0 到 Matches(z).SubMatches.Count-1结果 = 结果 &"Matches(" & z & ").SubMatches(" & zz & ") = " &chr(34) &Server.HTMLEncode(Matches(z).SubMatches(zz)) &chr(34) &铬(13)下一个结果=左(结果，Len(结果)-1)&铬(13)下一个Response.Write "
"&结果
使用非 java 表达式匹配
第 0 组获取包含逗号的整个子字符串
如果使用过，第 1 组将获得报价
第 2 组获取不包括逗号的值
[0][0] = 123[0][1] =[0][2] = 123[1][0] = ,2.99[1][1] =[1][2] = 2.99[2][0] = ,AMO024[2][1] =[2][2] = AMO024[3][0] = ,标题[3][1] =[3][2] = 标题[4][0] = ,"说明，更多信息"[4][1] = "[4][2] = 描述，更多信息[5][0] = ,[5][1] =[5][2] =[6][0] = ,123987564[6][1] =[6][2] = 123987564
I know this (or similar) has been asked many times but having tried out numerous possibilities I've not been able to find a a regex that works 100%.

I've got a CSV file and I'm trying to split it into an array, but encountering two problems: quoted commas and empty elements.

The CSV looks like:
123,2.99,AMO024,Title,"Description, more info",,123987564
The regex I've tried to use is:
thisLine.split(/,(?=(?:[^"]*"[^"]*")*(?![^"]*"))/)
The only problem is that in my output array the 5th element comes out as 123987564 and not an empty string.
解决方案
Description

Instead of using a split, I think it would be easier to simply execute a match and process all the found matches.

This expression will:


divide your sample text on the comma delimits
will process empty values
will ignore double quoted commas, providing double quotes are not nested
trims the delimiting comma from the returned value
trims surrounding quotes from the returned value


Regex:  (?:^|,)(?=[^"]|(")?)"?((?(1)[^"]*|[^,"]*))"?(?=,|$)



Example

Sample Text
123,2.99,AMO024,Title,"Description, more info",,123987564
ASP example using the non-java expression
Set regEx = New RegExp
regEx.Global = True
regEx.IgnoreCase = True
regEx.MultiLine = True
sourcestring = "your source string"
regEx.Pattern = "(?:^|,)(?=[^""]|("")?)""?((?(1)[^""]*|[^,""]*))""?(?=,|$)"
Set Matches = regEx.Execute(sourcestring)
  For z = 0 to Matches.Count-1
    results = results & "Matches(" & z & ") = " & chr(34) & Server.HTMLEncode(Matches(z)) & chr(34) & chr(13)
    For zz = 0 to Matches(z).SubMatches.Count-1
      results = results & "Matches(" & z & ").SubMatches(" & zz & ") = " & chr(34) & Server.HTMLEncode(Matches(z).SubMatches(zz)) & chr(34) & chr(13)
    next
    results=Left(results,Len(results)-1) & chr(13)
  next
Response.Write "<pre>" & results
Matches using the non-java expression

Group 0 gets the entire substring which includes the comma

Group 1 gets the quote if it's used

Group 2 gets the value not including the comma
[0][0] = 123
[0][1] = 
[0][2] = 123

[1][0] = ,2.99
[1][1] = 
[1][2] = 2.99

[2][0] = ,AMO024
[2][1] = 
[2][2] = AMO024

[3][0] = ,Title
[3][1] = 
[3][2] = Title

[4][0] = ,"Description, more info"
[4][1] = "
[4][2] = Description, more info

[5][0] = ,
[5][1] = 
[5][2] = 

[6][0] = ,123987564
[6][1] = 
[6][2] = 123987564


                        
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