Golang : Convert CSV data to JSON format and save to file
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
See also : Convert JSON to CSV in Golang
By Adam Ng
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