我想转换有值数组的json。 的 response.json
"New Visitor","(not set)","(not set)","0"
"New Visitor","(not set)","(not set)","mobile"
"New Visitor","(not set)","(not set)","mobile"
"New Visitor","(not set)","(not set)","mobile"
现在我想将这些数据转换成。 的 name.csv
0请使用Node.js给我建议。
答案 0 :(得分：16)
'use strict';
var fs = require('fs');
let myObj = {
"rows": [
[
"New , Visitor",
"(not set)",
"(not set)",
"0"
],
[
"New Visitor",
"(not set)",
"(not set)",
"mobile"
],
[
"New Visitor",
"(not set)",
"(not set)",
"mobile"
],
[
"New Visitor",
"(not set)",
"(not set)",
"mobile",
]
]
}
// 1. One way - if you want the results to be in double quotes and you have comas inside
// choose another string to temporally replace commas if necessary
let stringToReplaceComas = '!!!!';
myObj.rows.map((singleRow) => {
singleRow.map((value, index) => {
singleRow[index] = value.replace(/,/g, stringToReplaceComas);
})
})
let csv = `"${myObj.rows.join('"\n"').replace(/,/g, '","')}"`;
// // or like this
// let csv = `"${myObj.rows.join('"\n"').split(',').join('","')}"`;
csv = csv.replace(new RegExp(`${stringToReplaceComas}`, 'g'), ',');
// // 2. Another way - if you don't need the double quotes in the generated csv and you don't have comas in rows' values
// let csv = myObj.rows.join('\n')
fs.writeFile('name.csv', csv, 'utf8', function(err) {
if (err) {
console.log('Some error occured - file either not saved or corrupted file saved.');
} else {
console.log('It\'s saved!');
}
});
离。 https://github.com/mrodrig/json-2-csv，https://github.com/wdavidw/node-csv，https://github.com/wdavidw/node-csv-stringify
使用json-2-csv（https://github.com/mrodrig/json-2-csv）
的示例'use strict';
const converter = require('json-2-csv');
let myObj = {
"rows": [
{
value1: "New Visitor",
value2: "(not set)",
value3: "(not set)",
value4: "0"
},
{
value1: "New Visitor",
value2: "(not set)",
value3: "(not set)",
value4: "mobile"
},
{
value1: "New Visitor",
value2: "(not set)",
value3: "(not set)",
value4: "mobile"
},
{
value1: "New Visitor",
value2: "(not set)",
value3: "(not set)",
value4: "mobile",
}
]
}
let json2csvCallback = function (err, csv) {
if (err) throw err;
fs.writeFile('name.csv', output, 'utf8', function(err) {
if (err) {
console.log('Some error occured - file either not saved or corrupted file saved.');
} else {
console.log('It\'s saved!');
}
});
};
converter.json2csv(myObj.rows, json2csvCallback, {
prependHeader: false // removes the generated header of "value1,value2,value3,value4" (in case you don't want it)
});
使用csv-stringify（https://github.com/wdavidw/node-csv-stringify）
的示例'use strict';
var stringify = require('csv-stringify');
var fs = require('fs');
let myObj = {
"rows": [
[
"New Visitor",
"(not set)",
"(not set)",
"0"
],
[
"New Visitor",
"(not set)",
"(not set)",
"mobile"
],
[
"New Visitor",
"(not set)",
"(not set)",
"mobile"
],
[
"New Visitor",
"(not set)",
"(not set)",
"mobile",
]
]
}
stringify(myObj.rows, function(err, output) {
fs.writeFile('name.csv', output, 'utf8', function(err) {
if (err) {
console.log('Some error occured - file either not saved or corrupted file saved.');
} else {
console.log('It\'s saved!');
}
});
});
答案 1 :(得分：5)
第1步：阅读。
如果您需要从文件中读取JSON（如您在帖子中包含文件名response.json所示），则需要Node.js FileSystem API：
const fs = require('fs'); // Require Node.js FileSystem API.
const JSONFile = fs.readFileSync('response.json'); // Read the file synchronously.
注意：如果您愿意，可以使用fs.readFile()异步读取文件，并在回调函数中执行转换。
第2步：转换。
无论是从本地文件读取JSON还是从服务器获取JSON，您都需要先使用JSON.parse方法将其解析为普通的旧JavaScript对象：
const JSONasPOJO = JSON.parse(JSONFile); // Parse JSON into POJO.
然后对子数组和父数组执行一系列连接：
参见编辑以下
/* THIS IS UNNECESSARY FOR "COMMA" SEPARATED VALUES
const CSVString = JSONasPOJO
.rows // Get `rows`, which is an array.
.map( // Map returns a new array.
row => row.join(',') // Each child array becomes a comma-separated string.
)
.join('\n'); // Parent array becomes a newline-separated string...
// ...of comma-separated strings.
// It is now a single CSV string!
*/
修改
虽然前面的代码确实有效，但是没有必要在子数组上使用.map和.join。作为@Relu demonstrates，父数组上的单个.join就足够了，因为JavaScript会自动将子数组转换为逗号分隔的字符串，因为.join必须返回一个字符串且不能包含任何子字符串阵列。
如果要使用逗号以外的其他内容连接子数组，可以使用上一个方法。
否则：
var CSVString = JSONasPOJO.rows.join('\n'); // Array becomes a newline-separated...
// ...string of comma-separated strings.
// It is now a single CSV string!
在这里，我们可以看到转化行动：
const JSONasPOJO = {
"rows": [
[
"New Visitor",
"(not set)",
"(not set)",
"0"
],
[
"New Visitor",
"(not set)",
"(not set)",
"mobile"
],
[
"New Visitor",
"(not set)",
"(not set)",
"mobile"
],
[
"New Visitor",
"(not set)",
"(not set)",
"mobile" // NOTE: Here I removed a trailing comma,
// ...which is invalid JSON!
]
]
}
const CSVString = JSONasPOJO.rows.join('\n');
console.log(CSVString);
第3步：写。
再次使用FileSystem API，写入文件，并记录错误或成功消息：
fs.writeFile('name.csv', CSVString, err => {
if (err) return console.log(err);
console.log('FILE SUCCESSFULLY WRITTEN!\n');
});
注意：在这里，我使用回调来演示异步模式，以记录我的错误和成功消息。如果您愿意，可以与fs.writeFileSync()同步编写文件。
我想在我的Node.js脚本中添加大量console.log()消息。
const fs = require('fs');
const inFilename = 'response.json',
outFilename = 'name.csv';
console.log('\nPreparing to read from ' + inFilename + ' ...');
const JSONContents = fs.readFileSync(inFilename);
console.log('READ:');
console.log(JSONContents);
console.log('\nPreparing to parse as JSON ...');
const JSONasPOJO = JSON.parse(JSONContents);
console.log('PARSED:');
console.log(JSONasPOJO);
console.log('\nPreparing to convert into CSV ...');
const CSVString = JSONasPOJO.rows.join('\n');
console.log('CONVERTED:');
console.log(CSVString);
console.log('\nPreparing to write to ' + outFilename + '...');
fs.writeFile(outFilename, CSVString, err => {
if (err) return console.log(err);
console.log('FILE SUCCESSFULLY WRITTEN!\n');
});
答案 2 :(得分：0)
我对你们不了解，但是我喜欢可以按预期工作且无需进行大量额外配置的小程序包，请尝试使用jsonexport，我认为这是最好的模块，它与对象，数组， ..及其快速！
安装
npm i --save jsonexport
用法
const jsonexport = require('jsonexport');
const fs = require('fs');
jsonexport([{
value1: "New Visitor",
value2: "(not set)",
value3: "(not set)",
value4: "0"
},
{
value1: "New Visitor",
value2: "(not set)",
value3: "(not set)",
value4: "mobile"
},
{
value1: "New Visitor",
value2: "(not set)",
value3: "(not set)",
value4: "mobile"
},
{
value1: "New Visitor",
value2: "(not set)",
value3: "(not set)",
value4: "mobile",
}], function(err, csv) {
if (err) return console.error(err);
fs.writeFile('output.csv', csv, function(err) {
if (err) return console.error(err);
console.log('output.csv saved');
});
});
答案 3 :(得分：-1)
我想分享从json数组构建csv字符串的最简单方法：
const data = [
{ a: 1, b: new Date(), c: 'a text' },
{
a: 1, b: new Date(), c: `string
with
return
carrier
and emoji ?
`
}
]
const header = Object.keys(data[0]).map(_ => JSON.stringify(_)).join(';') + '\n'
const outData = data.reduce((acc, row) => {
return acc + Object.values(row).map(_ => JSON.stringify(_)).join(';') + '\n'
}, header)
console.log(outData)
将打印此字符串：
"a";"b";"c"
1;"2020-03-25T08:49:04.280Z";"a text"
1;"2020-03-25T08:49:04.280Z";"string\n with\n return\n carrier\n and emoji ?\n "