Golang : Convert CSV data to JSON format and save to file



Tags : golang csv convert json

Need to load a CSV data file and save it to JSON encoded file or stream it out ... like to a http service ? This tutorial will cover just that :

The Golang code below will first read this data.csv data file :

  Adam,36,CEO
  Eve,34,CFO
  Mike,38,COO

and output to data.json file

  [
  {"Name":"Adam","Age":36,"Job":"CEO"},
  {"Name":"Eve","Age":34,"Job":"CFO"},
  {"Name":"Mike","Age":38,"Job":"COO"}
  ]

csv2json.go

 package main

 import (
 "encoding/csv"
 "encoding/json"
 "fmt"
 "os"
 "strconv"
 )

 type Employee struct {
 Name string
 Age  int
 Job  string
 }

 func main() {
 // read data from CSV file

 csvFile, err := os.Open("./data.csv")

 if err != nil {
 fmt.Println(err)
 }

 defer csvFile.Close()

 reader := csv.NewReader(csvFile)

 reader.FieldsPerRecord = -1

 csvData, err := reader.ReadAll()

 if err != nil {
 fmt.Println(err)
 os.Exit(1)
 }

 var oneRecord Employee
 var allRecords []Employee

 for _, each := range csvData {
 oneRecord.Name = each[0]
 oneRecord.Age, _ = strconv.Atoi(each[1]) // need to cast integer to string
 oneRecord.Job = each[2]
 allRecords = append(allRecords, oneRecord)
 }

 jsondata, err := json.Marshal(allRecords) // convert to JSON

 if err != nil {
 fmt.Println(err)
 os.Exit(1)
 }

 // sanity check
 // NOTE : You can stream the JSON data to http service as well instead of saving to file
 fmt.Println(string(jsondata))

 // now write to JSON file

 jsonFile, err := os.Create("./data.json")

 if err != nil {
 fmt.Println(err)
 }
 defer jsonFile.Close()

 jsonFile.Write(jsondata)
 jsonFile.Close()
 }

Output :

[{"Name":"Adam","Age":36,"Job":"CEO"},{"Name":"Eve","Age":34,"Job":"CFO"},{"Name":"Mike","Age":38,"Job":"COO"}]

References :

https://www.socketloop.com/references/golang-encoding-json-marshal-function-example

https://www.socketloop.com/tutorials/read-csv-file-go

  See also : Convert JSON to CSV in Golang



Tags : golang csv convert json

By Adam Ng

IF you gain some knowledge or the information here solved your programming problem. Please consider donating to the less fortunate or some charities that you like. Apart from donation, planting trees, volunteering or reducing your carbon footprint will be great too.


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