為什麼 Go 的 CSV 編寫器會為包含特殊字元的引用字串添加額外的引號？

Go 中帶引號的字串的奇怪CSV 編碼

此程式碼片段嘗試建立一個包含兩筆記錄的CSV 文件，一則記錄包含未加引號的字串，另一筆記錄包含帶引號的字串包含特殊字元的字串：

<code class="go">package main

import (
    "encoding/csv"
    "fmt"
    "log"
    "os"
)

func main() {
    f, err := os.Create("./test.csv")
    if err != nil {
        log.Fatal("Error: %s", err)
    }
    defer f.Close()

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

    record = make([]string, 0)
    record = append(record, "Quoted string")
    s = fmt.Sprintf("%q", s)
    record = append(record, s)
    fmt.Println(record)
    w.Write(record)

    w.Flush()
}</code>

但是，輸出包含帶引號的字串周圍的額外引號：

Unquoted string,"Cr@zy text with , and \ and "" etc"
Quoted string,"""Cr@zy text with , and \ and \"" etc"""

說明

此行為是CSV 的結果標準。根據規範，字段內的雙引號必須用雙引號轉義。因此，CSV 寫入器會自動對引號的字串中的雙引號進行轉義。

解決方案

CSV 讀取器會在解析過程中自動對雙引號進行轉義，因此無需擔心多餘的引號。引號的字串將被正確地解釋為：

"Cr@zy text with , and \ and \" etc"

範例

這是程式碼的改進版本，刪除了不必要的轉義：

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",
      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()
}

輸出

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]

以上是為什麼 Go 的 CSV 編寫器會為包含特殊字元的引用字串添加額外的引號？的詳細內容。更多資訊請關注PHP中文網其他相關文章！