Golang处理CSV文件怎么做 通过encoding/csv库解析结构化数据

encoding/csv

os

bufio

encoding/csv

users.csv

Name,Age,Email
Alice,30,alice@example.com
Bob,25,bob@example.com
Charlie,35,charlie@example.com

type User struct {
    Name  string
    Age   int
    Email string
}

csv.Reader

package main

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

func main() {
    file, err := os.Open("users.csv")
    if err != nil {
        log.Fatal("无法打开文件:", err)
    }
    defer file.Close()

    reader := csv.NewReader(file)

    // 跳过标题行
    _, err = reader.Read()
    if err != nil {
        log.Fatal("读取标题行失败:", err)
    }

    var users []User
    for {
        record, err := reader.Read()
        if err == io.EOF {
            break
        }
        if err != nil {
            log.Fatal("读取行失败:", err)
        }

        age, err := strconv.Atoi(record[1])
        if err != nil {
            log.Fatal("年龄转换失败:", err)
        }

        user := User{
            Name:  record[0],
            Age:   age,
            Email: record[2],
        }
        users = append(users, user)
    }

    // 打印结果
    for _, u := range users {
        fmt.Printf("%+v\n", u)
    }
}

reader.ReadAll()

records, err := reader.ReadAll()
if err != nil {
    log.Fatal("读取所有数据失败:", err)
}

var users []User
for i, record := range records {
    if i == 0 {
        continue // 跳过标题
    }
    age, _ := strconv.Atoi(record[1])
    users = append(users, User{
        Name:  record[0],
        Age:   age,
        Email: record[2],
    })
}

header, err := reader.Read()
if err != nil {
    log.Fatal("读取标题失败:", err)
}

// 建立列名到索引的映射
headerMap := make(map[string]int)
for i, name := range header {
    headerMap[name] = i
}

for {
    record, err := reader.Read()
    if err == io.EOF {
        break
    }
    if err != nil {
        log.Fatal("读取行失败:", err)
    }

    age, _ := strconv.Atoi(record[headerMap["Age"]])

    user := User{
        Name:  record[headerMap["Name"]],
        Age:   age,
        Email: record[headerMap["Email"]],
    }
    users = append(users, user)
}

csv.Writer

file, err := os.Create("output.csv")
if err != nil {
    log.Fatal("创建文件失败:", err)
}
defer file.Close()

writer := csv.NewWriter(file)
defer writer.Flush()

// 写入标题
writer.Write([]string{"Name", "Age", "Email"})

// 写入数据
for _, u := range users {
    writer.Write([]string{u.Name, strconv.Itoa(u.Age), u.Email})
}

var records [][]string
records = append(records, []string{"Name", "Age", "Email"})
for _, u := range users {
    records = append(records, []string{u.Name, strconv.Itoa(u.Age), u.Email})
}
writer.WriteAll(records)

csv.Reader

,

;

reader := csv.NewReader(file)
reader.Comma = ';' // 设置分隔符为分号