174 lines
3.7 KiB
Markdown
174 lines
3.7 KiB
Markdown
Go CSV
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=====
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The GoCSV package aims to provide easy serialization and deserialization functions to use CSV in Golang
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API and techniques inspired from https://godoc.org/gopkg.in/mgo.v2
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[](https://godoc.org/github.com/gocarina/gocsv)
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[](https://travis-ci.org/gocarina/gocsv)
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Installation
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=====
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```go get -u github.com/gocarina/gocsv```
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Full example
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=====
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Consider the following CSV file
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```csv
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client_id,client_name,client_age
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1,Jose,42
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2,Daniel,26
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3,Vincent,32
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```
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Easy binding in Go!
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---
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```go
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package main
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import (
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"fmt"
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"os"
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"github.com/gocarina/gocsv"
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)
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type NotUsed struct {
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Name string
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}
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type Client struct { // Our example struct, you can use "-" to ignore a field
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Id string `csv:"client_id"`
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Name string `csv:"client_name"`
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Age string `csv:"client_age"`
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NotUsedString string `csv:"-"`
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NotUsedStruct NotUsed `csv:"-"`
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}
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func main() {
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clientsFile, err := os.OpenFile("clients.csv", os.O_RDWR|os.O_CREATE, os.ModePerm)
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if err != nil {
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panic(err)
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}
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defer clientsFile.Close()
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clients := []*Client{}
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if err := gocsv.UnmarshalFile(clientsFile, &clients); err != nil { // Load clients from file
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panic(err)
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}
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for _, client := range clients {
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fmt.Println("Hello", client.Name)
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}
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if _, err := clientsFile.Seek(0, 0); err != nil { // Go to the start of the file
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panic(err)
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}
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clients = append(clients, &Client{Id: "12", Name: "John", Age: "21"}) // Add clients
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clients = append(clients, &Client{Id: "13", Name: "Fred"})
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clients = append(clients, &Client{Id: "14", Name: "James", Age: "32"})
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clients = append(clients, &Client{Id: "15", Name: "Danny"})
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csvContent, err := gocsv.MarshalString(&clients) // Get all clients as CSV string
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//err = gocsv.MarshalFile(&clients, clientsFile) // Use this to save the CSV back to the file
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if err != nil {
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panic(err)
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}
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fmt.Println(csvContent) // Display all clients as CSV string
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}
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```
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Customizable Converters
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---
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```go
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type DateTime struct {
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time.Time
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}
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// Convert the internal date as CSV string
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func (date *DateTime) MarshalCSV() (string, error) {
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return date.Time.Format("20060201"), nil
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}
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// You could also use the standard Stringer interface
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func (date *DateTime) String() (string) {
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return date.String() // Redundant, just for example
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}
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// Convert the CSV string as internal date
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func (date *DateTime) UnmarshalCSV(csv string) (err error) {
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date.Time, err = time.Parse("20060201", csv)
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return err
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}
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type Client struct { // Our example struct with a custom type (DateTime)
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Id string `csv:"id"`
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Name string `csv:"name"`
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Employed DateTime `csv:"employed"`
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}
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```
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Customizable CSV Reader / Writer
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---
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```go
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func main() {
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...
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gocsv.SetCSVReader(func(in io.Reader) gocsv.CSVReader {
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r := csv.NewReader(in)
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r.Comma = '|'
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return r // Allows use pipe as delimiter
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})
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...
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gocsv.SetCSVReader(func(in io.Reader) gocsv.CSVReader {
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r := csv.NewReader(in)
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r.LazyQuotes = true
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r.Comma = '.'
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return r // Allows use dot as delimiter and use quotes in CSV
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})
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...
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gocsv.SetCSVReader(func(in io.Reader) gocsv.CSVReader {
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//return csv.NewReader(in)
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return gocsv.LazyCSVReader(in) // Allows use of quotes in CSV
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})
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...
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gocsv.UnmarshalFile(file, &clients)
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...
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gocsv.SetCSVWriter(func(out io.Writer) *gocsv.SafeCSVWriter {
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writer := csv.NewWriter(out)
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writer.Comma = '|'
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return gocsv.NewSafeCSVWriter(writer)
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})
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...
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gocsv.MarshalFile(&clients, file)
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...
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}
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```
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