Go CSV

The GoCSV package aims to provide easy serialization and deserialization functions to use CSV in Golang

API and techniques inspired from https://godoc.org/gopkg.in/mgo.v2

Installation

Full example
=====

Consider the following CSV file

```csv

client_id,client_name,client_age
1,Jose,42
2,Daniel,26
3,Vincent,32

Easy binding in Go!

package main

import (
    "fmt"
    "gocsv"
    "os"
)

type Client struct { // Our example struct, you can use "-" to ignore a field
    Id      string `csv:"client_id"`
    Name    string `csv:"client_name"`
    Age     string `csv:"client_age"`
    NotUsed string `csv:"-"`
}

func main() {
    clientsFile, err := os.OpenFile("clients.csv", os.O_RDWR|os.O_CREATE, os.ModePerm)
    if err != nil {
        panic(err)
    }
    defer clientsFile.Close()

    clients := []*Client{}

    if err := gocsv.UnmarshalFile(clientsFile, &clients); err != nil { // Load clients from file
        panic(err)
    }
    for _, client := range clients {
        fmt.Println("Hello", client.Name)
    }

    if _, err := clientsFile.Seek(0, 0); err != nil { // Go to the start of the file
        panic(err)
    }

    clients = append(clients, &Client{Id: "12", Name: "John", Age: "21"}) // Add clients
    clients = append(clients, &Client{Id: "13", Name: "Fred"})
    clients = append(clients, &Client{Id: "14", Name: "James", Age: "32"})
    clients = append(clients, &Client{Id: "15", Name: "Danny"})
    csvContent, err := gocsv.MarshalString(&clients) // Get all clients as CSV string
    //err = gocsv.MarshalFile(&clients, clientsFile) // Use this to save the CSV back to the file
    if err != nil {
        panic(err)
    }
    fmt.Println(csvContent) // Display all clients as CSV string

}

Customizable Converters

type DateTime struct {
    time.Time
}

// Convert the internal date as CSV string
func (date *DateTime) MarshalCSV() (string, error) {
    return date.Time.Format("20060201"), nil
}

// You could also use the standard Stringer interface 
func (date *DateTime) String() (string) {
    return date.String() // Redundant, just for example
}

// Convert the CSV string as internal date
func (date *DateTime) UnmarshalCSV(csv string) (err error) {
    date.Time, err = time.Parse("20060201", csv)
    if err != nil {
        return err
    }
    return nil
}

type Client struct { // Our example struct with a custom type (DateTime)
    Id       string   `csv:"id"`
    Name     string   `csv:"name"`
    Employed DateTime `csv:"employed"`
}

Customizable CSV Reader / Writer

func main() {
        ...
    
        gocsv.SetCSVReader(func(in io.Reader) gocsv.CSVReader {
            r := csv.NewReader(in)
            r.Comma = '|'
            return r // Allows use pipe as delimiter
        })    
    
        ...
    
        gocsv.SetCSVReader(func(in io.Reader) gocsv.CSVReader {
            r := csv.NewReader(in)
            r.LazyQuotes = true
            r.Comma = '.'
            return r // Allows use dot as delimiter and use quotes in CSV
        })
    
        ...
    
        gocsv.SetCSVReader(func(in io.Reader) gocsv.CSVReader {
            //return csv.NewReader(in)
            return gocsv.LazyCSVReader(in) // Allows use of quotes in CSV
        })

        ...

        gocsv.UnmarshalFile(file, &clients)

        ...

        gocsv.SetCSVWriter(func(out io.Writer) *SafeCSVWriter {
            writer := csv.NewWriter(out)
            writer.Comma = '|'
            return gocsv.NewSafeCSVWriter(writer)
        })

        ...

        gocsv.MarshalFile(&clients, file)

        ...
}