nodejs 创建csv并下载

nodejs服务器端，创建csv并下载的方法:

var readStr = fs.readFileSync('./public/3-1data_img.txt');    var readObj = eval("("+readStr+")");    var label = readObj["pie_chart"]["p_label"];    var value = readObj["pie_chart"]["r_default"];    var data = [];    data[0] = label;    data[1] = value;    console.log(data);res.setHeader('Content-disposition', 'attachment; filename=all_student.csv');    res.writeHead(200, {        'Content-Type': 'text/csv'    });    res.write(new Buffer('\xEF\xBB\xBF','binary'));//add utf-8 bom    csv().from.array(data).to(res);