Strange CSV result for quoted strings in go encoding/csv

csv, escaping, go, string

Solution

It's part of the standard for storing data as CSV. Double quote characters need to be escaped for parsing reasons.

A (double) quote character in a field must be represented by two (double) quote characters.

From: http://en.wikipedia.org/wiki/Comma-separated_values

You don't really have to worry because the CSV reader un-escapes the double quote.

Example:

package main

import (
    "encoding/csv"
    "fmt"
    "os"
)
func checkError(e error){
    if e != nil {
        panic(e)
    }
}
func writeCSV(){
    fmt.Println("Writing csv")
    f, err := os.Create("./test.csv")
    checkError(err)
    defer f.Close()

    w := csv.NewWriter(f)
    s := "Cr@zy text with , and \\ and \" etc"
    record := []string{ 
      "Unquoted string",
      s,
    }
    fmt.Println(record)
    w.Write(record)

    record = []string{ 
      "Quoted string",
      fmt.Sprintf("%q",s),
    }
    fmt.Println(record)
    w.Write(record)
    w.Flush()
}
func readCSV(){
    fmt.Println("Reading csv")
    file, err := os.Open("./test.csv")
    defer file.Close();
    cr := csv.NewReader(file)
    records, err := cr.ReadAll()
    checkError(err)
    for _, record := range records {
        fmt.Println(record)
    }
}
func main() {
   writeCSV()
   readCSV()
}

Output

Writing csv
[Unquoted string Cr@zy text with , and \ and " etc]
[Quoted string "Cr@zy text with , and \\ and \" etc"]
Reading csv
[Unquoted string Cr@zy text with , and \ and " etc]
[Quoted string "Cr@zy text with , and \\ and \" etc"]

Here's the code for the write function. func (w *Writer) Write(record []string) (err error)

Problem

Original source