转换CSV文件到JSON字典？
我需要将大型CSV数据集转换为JSON，但输出结果应该是这样的JSON字典：
var products = { "crystal": { "description": "This is a crystal", "price": "2.95" }, "emerald": { "description": "This is a emerald", "price": "5.95" } }; 这就是CSV表格的样子： 
我正在使用这里引用的脚本来生成JSON：
var csv = require('csv') var fs = require('fs') var f = fs.createReadStream('Fielding.csv') var w = fs.createWriteStream('out.txt') w.write('['); csv() .from.stream(f, {columns:true}) .transform(function(row, index) { return (index === 0 ? '' : ',\n') + JSON.stringify(row); }) .to.stream(w, {columns: true, end: false}) .on('end', function() { w.write(']'); w.end(); });
但是，该脚本的输出是以这种格式创build的：
[ { "name": "crystal", "description": "This is a crystal", "price": "2.95" }, { "name": "emerald", "description": "This is a emerald", "price": "5.95" } ]
我将如何修改脚本来获得我想要的“字典”格式？
所有你需要做的是遍历数组，并使用item.name作为你的字典对象的关键
var products ={}; data.forEach(function(item){ products[item.name] = item; });
这将使name属性留在项目中，但这不应该是一个问题
我认为这样的事情会起作用：
var products_arr = [{"name":"crystal","description":"This is a crystal","price":"2.95"}, {"name":"emerald","description":"This is a emerald","price":"5.95"}] var products = {}; for (var i = 0, l = products_arr.length ; i < l ; ++i) { var x = products_arr[i]; var name = x.name delete x.name; // deletes name property from JSON object products[name] = x; }
这将输出：
{ "crystal": { "description": "This is a crystal", "price": "2.95" }, "emerald": { "description": "This is a emerald", "price": "5.95" } }
我发现csv分析器库最有用：
var csvText=`status,path,name,ext,checksum,size,document_service_id,document_service_path,message success,./15-02-2017_17-11/d77c7886-ffe9-40f2-b2fe-e68410d07891//expE1.txt,expE1.txt,txt,38441337865069eabae7754b29bb43e1,414984,8269f7e3-3221-49bb-bb5a-5796cf208fd1,/neuroinftest/20170215/expE1.txt, success,./15-02-2017_17-11/d77c7886-ffe9-40f2-b2fe-e68410d07891//expE10.txt,expE10.txt,txt,f27e46979035706eb0aaf58c26e09585,368573,2c94ed19-29c9-4660-83cf-c2148c3d6f61,/neuroinftest/20170215/expE10.txt, success,./15-02-2017_17-11/d77c7886-ffe9-40f2-b2fe-e68410d07891//expE2.txt,expE2.txt,txt,e1040d9546423c823944120de0e5c46c,333308,b3898f5d-1058-4cf3-acf9-76759117b810,/neuroinftest/20170215/expE2.txt, ` var csv = require('csv'); csv.parse(csvText, {columns: true}, function(err, data){ console.log(JSON.stringify(data, null, 2)); });
在variablescsvText我有我的逗号分隔的文件，第一行作为标题。 我使用parse函数，并传递{columns: true}来表示第一行有标题。 callback函数（ data ）中的第二个参数的对象的键是标题，值是相应的csv单元格。 我使用JSON.stringify很好地打印它，结果对象看起来像这样（它把它放入一个数组）：
[ { "status": "success", "path": "./15-02-2017_17-11/d77c7886-ffe9-40f2-b2fe-e68410d07891//expE1.txt", "name": "expE1.txt", "ext": "txt", "checksum": "38441337865069eabae7754b29bb43e1", "size": "414984", "document_service_id": "8269f7e3-3221-49bb-bb5a-5796cf208fd1", "document_service_path": "/neuroinftest/20170215/expE1.txt", "message": "" }, { "status": "success", "path": "./15-02-2017_17-11/d77c7886-ffe9-40f2-b2fe-e68410d07891//expE10.txt", "name": "expE10.txt", "ext": "txt", "checksum": "f27e46979035706eb0aaf58c26e09585", "size": "368573", "document_service_id": "2c94ed19-29c9-4660-83cf-c2148c3d6f61", "document_service_path": "/neuroinftest/20170215/expE10.txt", "message": "" }, { "status": "success", "path": "./15-02-2017_17-11/d77c7886-ffe9-40f2-b2fe-e68410d07891//expE2.txt", "name": "expE2.txt", "ext": "txt", "checksum": "e1040d9546423c823944120de0e5c46c", "size": "333308", "document_service_id": "b3898f5d-1058-4cf3-acf9-76759117b810", "document_service_path": "/neuroinftest/20170215/expE2.txt", "message": "" } ]
UPD ：这个数组可以很容易地变成你需要的对象：
var res_obj = data.reduce(function(acc, cur, i) { acc[cur.name] = cur; return acc; }, {});
在我的情况下，我使用名称属性作为一个关键。 确保它是唯一的。
如果您想修改您的特定代码，则可以更改该行
return (index === 0 ? '' : ',\n') + JSON.stringify(row);
至
var clonedRow = JSON.parse(JSON.stringify(row)); var key = clonedRow['name']; delete clonedRow['name']; var newRow = {}; newRow[key] = clonedRow; return (index === 0 ? '' : ',\n') + JSON.stringify(newRow);
这将为每行创build一个新的对象，根据您的要求修改结构。
你最好的select是使用PapaParse ，一个function强大的CSVparsing器/翻车机。 它支持stream，各种string编码，标题行，而且速度很快。