How to convert CSV to JSON in Node.js
JavascriptJsonnode.jsCsvExpressJavascript Problem Overview
I am trying to convert csv file to json. I am using .
Example CSV:
a,b,c,d
1,2,3,4
5,6,7,8
...
Desired JSON:
{"a": 1,"b": 2,"c": 3,"d": 4},
{"a": 5,"b": 6,"c": 7,"d": 8},
...
I tried node-csv parser library.But the output is like array not like I expected.
I'm using Node 0.8 and express.js and would like a recommendation on how to easily accomplish this.
Javascript Solutions
Solution 1 - Javascript
Node.js csvtojson
module is a comprehensive nodejs csv parser. It can be used as node.js app library / a command line tool / or browser with help of browserify
or webpack
.
the source code can be found at: https://github.com/Keyang/node-csvtojson
It is fast with low memory consumption yet powerful to support any of parsing needs with abundant API and easy to read documentation.
The detailed documentation can be found here
Here are some code examples:
Use it as a library in your Node.js application ([email protected] +):
- Install it through
npm
- Use it in your node.js app:
// require csvtojson
var csv = require("csvtojson");
// Convert a csv file with csvtojson
csv()
.fromFile(csvFilePath)
.then(function(jsonArrayObj){ //when parse finished, result will be emitted here.
console.log(jsonArrayObj);
})
// Parse large csv with stream / pipe (low mem consumption)
csv()
.fromStream(readableStream)
.subscribe(function(jsonObj){ //single json object will be emitted for each csv line
// parse each json asynchronousely
return new Promise(function(resolve,reject){
asyncStoreToDb(json,function(){resolve()})
})
})
//Use async / await
const jsonArray=await csv().fromFile(filePath);
Use it as a command-line tool:
sh# npm install csvtojson
sh# ./node_modules/csvtojson/bin/csvtojson ./youCsvFile.csv
-or-
sh# npm install -g csvtojson
sh# csvtojson ./yourCsvFile.csv
For advanced usage:
sh# csvtojson --help
You can find more details from the github page above.
Solution 2 - Javascript
You can try to use underscore.js
First convert the lines in arrays using the toArray function :
var letters = _.toArray(a,b,c,d);
var numbers = _.toArray(1,2,3,4);
Then object the arrays together using the object function :
var json = _.object(letters, numbers);
By then, the json var should contain something like :
{"a": 1,"b": 2,"c": 3,"d": 4}
Solution 3 - Javascript
Had to do something similar, hope this helps.
// Node packages for file system
var fs = require('fs');
var path = require('path');
var filePath = path.join(__dirname, 'PATH_TO_CSV');
// Read CSV
var f = fs.readFileSync(filePath, {encoding: 'utf-8'},
function(err){console.log(err);});
// Split on row
f = f.split("\n");
// Get first row for column headers
headers = f.shift().split(",");
var json = [];
f.forEach(function(d){
// Loop through each row
tmp = {}
row = d.split(",")
for(var i = 0; i < headers.length; i++){
tmp[headers[i]] = row[i];
}
// Add object to list
json.push(tmp);
});
var outPath = path.join(__dirname, 'PATH_TO_JSON');
// Convert object to string, write json to file
fs.writeFileSync(outPath, JSON.stringify(json), 'utf8',
function(err){console.log(err);});
Solution 4 - Javascript
Here is a solution that does not require a separate module. However, it is very crude, and does not implement much error handling. It could also use more tests, but it will get you going. If you are parsing very large files, you may want to seek an alternative. Also, see this solution from Ben Nadel.
Node Module Code, csv2json.js:
/*
* Convert a CSV String to JSON
*/
exports.convert = function(csvString) {
var json = [];
var csvArray = csvString.split("\n");
// Remove the column names from csvArray into csvColumns.
// Also replace single quote with double quote (JSON needs double).
var csvColumns = JSON
.parse("[" + csvArray.shift().replace(/'/g, '"') + "]");
csvArray.forEach(function(csvRowString) {
var csvRow = csvRowString.split(",");
// Here we work on a single row.
// Create an object with all of the csvColumns as keys.
jsonRow = new Object();
for ( var colNum = 0; colNum < csvRow.length; colNum++) {
// Remove beginning and ending quotes since stringify will add them.
var colData = csvRow[colNum].replace(/^['"]|['"]$/g, "");
jsonRow[csvColumns[colNum]] = colData;
}
json.push(jsonRow);
});
return JSON.stringify(json);
};
Jasmine Test, csv2jsonSpec.js:
var csv2json = require('csv2json.js');
var CSV_STRING = "'col1','col2','col3'\n'1','2','3'\n'4','5','6'";
var JSON_STRING = '[{"col1":"1","col2":"2","col3":"3"},{"col1":"4","col2":"5","col3":"6"}]';
/* jasmine specs for csv2json */
describe('csv2json', function() {
it('should convert a csv string to a json string.', function() {
expect(csv2json.convert(CSV_STRING)).toEqual(
JSON_STRING);
});
});
Solution 5 - Javascript
Using ES6
const toJSON = csv => {
const lines = csv.split('\n')
const result = []
const headers = lines[0].split(',')
lines.map(l => {
const obj = {}
const line = l.split(',')
headers.map((h, i) => {
obj[h] = line[i]
})
result.push(obj)
})
return JSON.stringify(result)
}
const csv = `name,email,age
francis,[email protected],33
matty,[email protected],29`
const data = toJSON(csv)
console.log(data)
Output
// [{"name":"name","email":"email","age":"age"},{"name":"francis","email":"[email protected]","age":"33"},{"name":"matty","email":"[email protected]","age":"29"}]
Solution 6 - Javascript
Using lodash:
function csvToJson(csv) {
const content = csv.split('\n');
const header = content[0].split(',');
return _.tail(content).map((row) => {
return _.zipObject(header, row.split(','));
});
}
Solution 7 - Javascript
If you want just a command line converter, the quickest and most clean solution for me is to use csvtojson via npx (included by default in node.js)
Solution 8 - Javascript
I haven't tried csv package https://npmjs.org/package/csv but according to documentation it looks quality implementation http://www.adaltas.com/projects/node-csv/
Solution 9 - Javascript
I started with node-csvtojson, but it brought too many dependencies for my linking.
Building on your question and the answer by brnd, I used node-csv and underscore.js.
var attribs;
var json:
csv()
.from.string(csvString)
.transform(function(row) {
if (!attribs) {
attribs = row;
return null;
}
return row;
})
.to.array(function(rows) {
json = _.map(rows, function(row) {
return _.object(attribs, row);
});
});
Solution 10 - Javascript
I have a very simple solution to just print json from csv on console using csvtojson module.
// require csvtojson
var csv = require("csvtojson");
const csvFilePath='customer-data.csv' //file path of csv
csv()
.fromFile(csvFilePath)``
.then((jsonObj)=>{
console.log(jsonObj);
})
Solution 11 - Javascript
Node-ETL package is enough for all BI processing.
npm install node-etl;
Then :
var ETL=require('node-etl');
var output=ETL.extract('./data.csv',{
headers:["a","b","c","d"],
ignore:(line,index)=>index!==0, //ignore first line
});
Solution 12 - Javascript
I have used csvtojson library for converting csv string to json array.
It has variety of function which can help you to convert to JSON.
It also supports reading from file and file streaming.
Be careful while parsing the csv which can contain the comma(,) or any other delimiter . For removing the delimiter please see my answer here.
Solution 13 - Javascript
Step 1:
Install node module: npm install csvtojson --save
Step 2:
var Converter = require("csvtojson").Converter;
var converter = new Converter({});
converter.fromFile("./path-to-your-file.csv",function(err,result){
if(err){
console.log("Error");
console.log(err);
}
var data = result;
//to check json
console.log(data);
});
Solution 14 - Javascript
Me and my buddy created a web service to handle this kind of thing.
Check out Modifly.co for instructions on how to transform CSV to JSON with a single RESTful call.
Solution 15 - Javascript
Use csv parser library, I'm explaining in more details how to use it here .
var csv = require('csv');
csv.parse(csvText, {columns: true}, function(err, data){
console.log(JSON.stringify(data, null, 2));
});
Solution 16 - Javascript
npm install csvjson --save
In you Node JS File
const csvjson = require('csvjson');
convertCSVToJSON(*.csv);
convertCSVToJSON = (file) => {
const convertedObj = csvjson.toObject(file);
}
Solution 17 - Javascript
csvtojson module is a comprehensive nodejs csv parser to convert csv to json or column arrays. It can be used as node.js library / command line tool / or in browser. Below are some features:
/** csv file
a,b,c
1,2,3
4,5,6
*/
const csvFilePath='<path to csv file>'
const csv=require('csvtojson')
csv()
.fromFile(csvFilePath)
.then((jsonObj)=>{
console.log(jsonObj);
/**
* [
* {a:"1", b:"2", c:"3"},
* {a:"4", b:"5". c:"6"}
* ]
*/
})
// Async / await usage
const jsonArray=await csv().fromFile(csvFilePath);