Question

我有一个我需要解析的CSV文件类型。以下是我需要考虑的条件（缺少列标题，引号内的换行符，缺少数据等）：

ID,NAME,TITLE,DESCRIPTION,,
PRO1234,"JOHN SMITH",ENGINEER,"JOHN HAS BEEN WORKING

HARD ON BEING A GOOD

SERVENT."
PRO1235,"KEITH SMITH",ENGINEER,"keith has been working

hard on being a good

servent."
PRO1235,"KENNY SMITH",,"keith has been working

hard on being a good

servent."
PRO1235,"RICK SMITH",,,

您会注意到说明中有换行符以及新行数据的换行符。

我已经编写了这个正则表达式来查找引号OUTSIDE的换行符，并且效果很好here

代码，使用Node.js：

var fs = require('fs');

function parseCSV(filename){
    var rx = new RegExp(/\n(?=([^"\\]*(\\.|"([^"\\]*\\.)*[^"\\]*"))*[^"]*$)/g);
    var strFile = fs.readFileSync(filename).toString();
    console.log("line feed count via match: " + strFile.match(rx).length);
    var csv = strFile.split(rx);

    console.log("csv length: " + csv.length);
    console.log("csv items ###############################");
    csv.forEach(function(e,i,a){
        console.log("item e: " + e);
    });
}

当我运行此功能时，您会看到换行计数（匹配找到的换行）正确， 4 。但是，当使用与String.split（）相同的ret时，它会返回 17 ，结果数组不稳定：

line feed count via match: 4
csv length: 17
csv items ###############################
item e: ID,NAME,TITLE,DESCRIPTION,,
item e: 
PRO1235,"RICK SMITH"
item e: "RICK SMITH"
item e: undefined
item e: PRO1234,"JOHN SMITH",ENGINEER,"JOHN HAS BEEN WORKING

HARD ON BEING A GOOD

SERVENT."
item e: 
PRO1235,"RICK SMITH"
item e: "RICK SMITH"
item e: undefined
item e: PRO1235,"KEITH SMITH",ENGINEER,"keith has been working

hard on being a good

servent."
item e: 
PRO1235,"RICK SMITH"
item e: "RICK SMITH"
item e: undefined
item e: PRO1235,"KENNY SMITH",,"keith has been working

hard on being a good

servent."
item e: PRO1235,"RICK SMITH"
item e: "RICK SMITH"
item e: undefined
item e: PRO1235,"RICK SMITH",,,

分手时我做错了什么？我的想法是，如果我能识别出与match（）完美匹配的4个换行符，那么相同的regEx应该提供“拆分”字符串的位置。

Answer 1

你有太多的捕获组。拆分将在分割字符串时返回捕获的组。请考虑以下简单示例：

var simpleString = "111aaa222bbb";
var regxNoCaptureGroup = /\d+/;
var regxWithCaptureGroup = /(\d+)/;
var regxWithNoncapturingGroup = /(?:\d+)/;

simpleString.split(regxNoCaptureGroup); //["", "aaa", "bbb"]
simpleString.split(regxWithNoncapturingGroup); //same as above
simpleString.split(regxWithCaptureGroup); //["", "111", "aaa", "222", "bbb"]  - includes captured groups

您在捕获组中拥有捕获组。请记住，拆分将找到该组，并将其删除以找到拆分部分，因此拆分数字（如第一个示例中）将仅返回字母。在您的情况下，它将删除捕获的任何内容。对于捕获组，它会在结果中返回它们 - 所以如果你计划在正则表达式中使用split，你应该建立一个只捕获所需内容的好的正则表达式。

Answer 2

感谢anubhava的回答，这很好用：

var $ = jQuery = require('jquery');
var csv = require('./jquery.csv-0.71.min.js');
var fs = require('fs');

var strFile = fs.readFileSync("./data/TestData.csv").toString();
var obj = $.csv.toObjects(strFile);
var str = JSON.stringify(obj, null, 4);

console.log("str: " + str);

谁不喜欢新的轮子？

在我的辩护中，我在节点上尝试了3个工具，并且所有3个工具都是针对原始条件下最简单的情况和文件编写的。

RegExp与String.match一起使用，但不适用于String.split

2 个答案: