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）已被问过很多次，但尝试了许多可能性，我没有能够找到一个工作100％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：引用逗号和空元素。

CSV看起来像：

  123,2.99，AMO024，标题，说明，更多信息,, 123987564 
  

我试图使用的正则表达式是：

 code> thisLine.split（/，（？=（？：[^ \] * \[^ \] * \）*（？！[^ \] * \\））/）
  

唯一的问题是在我的输出数组中第5个元素123987564而不是空字符串。

解决方案

描述

使用分割，我认为简单地执行匹配并处理所有找到的匹配将更容易。

此表达式将：

• 在逗号分隔符上分隔您的示例文本


• 将处理空值




• 修剪返回值的周围引号

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

示例

示例文本

  123,2.99，AMO024，标题，说明，更多信息,, 123987564 
  

ASP示例使用非java表达式

 设置regEx =新的RegExp 
 regEx.Global = True 
 regEx.IgnoreCase = True 
 regEx.MultiLine = True 
 sourcestring =您的源字符串
 regEx.Pattern =（？：^ |，）（？= [^] | ）？？？（？（1）[^] * | [^，] *）） sourcestring）
对于z = 0到Matches.Count-1 
 results = results& Matches（& z&）=& chr（34）& Server.HTMLEncode（Matches（z））& chr（34）& chr（13）
对于zz = 0到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 
  

使用非java表达式匹配
$ b

组0获取包含逗号的整个子字符串

组1获取引用的引用

组2获取的值不包括逗号

  [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] 
 [4] [1] =
 [4] [2] =描述，更多信息
 
 [5] [0] =，
 [5] [1] = 
 [5] [2] = 
 
 [6] [0] =，123987564 
 [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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