golang正则之命名分组方式

str := `Alice 20 alice@gmail.com`
// 使用命名分组，显得更清晰
re := regexp.MustCompile(`(?P<name>[a-zA-Z]+)\s+(?P<age>\d+)\s+(?P<email>\w+@\w+(?:\.\w+)+)`)
match := re.FindStringSubmatch(str)
groupNames := re.SubexpNames()
fmt.Printf("%v, %v, %d, %d\n", match, groupNames, len(match), len(groupNames))
result := make(map[string]string)
// 转换为map
for i, name := range groupNames {
    if i != 0 && name != "" { // 第一个分组为空（也就是整个匹配）
        result[name] = match[i]
    }
}
prettyResult, _ := json.MarshalIndent(result, "", "  ")
fmt.Printf("%s\n", prettyResult)

[Alice 20 alice@gmail.com Alice 20 alice@gmail.com], [ name age email], 4, 4
{
  "age": "20",
  "email": "alice@gmail.com",
  "name": "Alice"
}

Alice 20 alice@gmail.com
Bob 25 bob@outlook.com
gerrylon 26 gerrylon@github.com
...
更多内容

// 文件内容直接用字符串表示
usersStr := `
    Alice 20 alice@gmail.com
    Bob 25 bob@outlook.com
    gerrylon 26 gerrylon@github.com
`
userRe := regexp.MustCompile(`(?P<name>[a-zA-Z]+)\s+(?P<age>\d+)\s+(?P<email>\w+@\w+(?:\.\w+)+)`)
// 这里要用FindAllStringSubmatch，找到所有的匹配
users := userRe.FindAllStringSubmatch(usersStr, -1)
groupNames := userRe.SubexpNames()
var result []map[string]string // slice of map
// 循环所有行
for _, user := range users {
    m := make(map[string]string)
    // 对每一行生成一个map
    for j, name := range groupNames {
        if j != 0 && name != "" {
            m[name] = strings.TrimSpace(user[j])
        }
    }
    result = append(result, m)
}
prettyResult, _ := json.MarshalIndent(result, "", "  ")
fmt.Println(string(prettyResult))

[
  {
    "age": "20",
    "email": "alice@gmail.com",
    "name": "Alice"
  },
  {
    "age": "25",
    "email": "bob@outlook.com",
    "name": "Bob"
  },
  {
    "age": "26",
    "email": "gerrylon@github.com",
    "name": "gerrylon"
  }
]

import (
   "encoding/json"
   "fmt"
   "regexp"
)

str := `9x_xx:995:88`  // `9x_xx:995`
// 使用命名分组，一次匹配多个值
re := regexp.MustCompile(`(?P<fname>\w+):+(?P<mod>[1-9]*):*(?P<strlen>[0-9]*)`)
match := re.FindStringSubmatch(str)
groupNames := re.SubexpNames()
fmt.Printf("%v, %v, %d, %d\n", match, groupNames, len(match), len(groupNames))
 
result := make(map[string]string)
if len(match) == len(groupNames) {
   // 转换为map
   for i, name := range groupNames {
      if i != 0 && name != "" { // 第一个分组为空（也就是整个匹配）
         result[name] = match[i]
      }
   }
}

prettyResult, _ := json.MarshalIndent(result, "", "  ") 
fmt.Printf("%s\n", prettyResult)