使用golang从文件中提取数据

Question

I am trying to extract lines from a file if a condition is met.

The data in the file look like this :

Sat 08 Aug 2015
Norwich City
A
League
    W 3-1
    Zaha 38; Delaney 48; Cabaye 90
    27,036

If the pattern of the date is matched, I want to print the following five lines.

My code is,

func main() {

    r, _ := regexp.Compile("[aA-zZ]{3}\\s[0-9]{2}\\s[aA-zZ]{3}\\s[0-9]{4}")

    file, err := os.Open("test.txt")
    if err != nil {
        log.Fatal(err)
    }
    defer file.Close()

    scanner := bufio.NewScanner(file)
    for scanner.Scan() {

        if r.MatchString(scanner.Text()) {

            fmt.Println(scanner.Text())

            // here how do i capture the following 5 lines

        }

        if err := scanner.Err(); err != nil {
            log.Fatal(err)
        }
    }
}

Answer 1

Perhaps, something like this?

package main

import (
    "bufio"
    "fmt"
    "io"
    "os"
    "strings"
    "time"
)

type Match struct {
    Date       time.Time
    Opponents  string
    Venue      string
    Type       string
    Result     string
    Scorers    string
    Attendance string
}

var fmtMatchDate = "Mon 02 Jan 2006"

func (m Match) String() string {
    var s string
    s += fmt.Sprint(m.Date.Format(fmtMatchDate), "
")
    s += fmt.Sprint(
        m.Opponents, "
",
        m.Venue, "
",
        m.Type, "
",
        m.Result, "
",
    )
    if len(m.Scorers) > 0 {
        s += fmt.Sprint(
            m.Scorers, "
",
        )
    }
    if len(m.Attendance) > 0 {
        s += fmt.Sprint(
            m.Attendance, "
",
        )
    }
    return s
}

func ParseMatch(lines []string) (Match, error) {
    // TODO: Implement a better parser.
    var m Match
    for i, line := range lines {
        line = strings.TrimSpace(line)
        switch i {
        case 0:
            date, err := time.Parse(fmtMatchDate, line)
            if err != nil {
                return Match{}, err
            }
            m.Date = date
        case 1:
            m.Opponents = line
        case 2:
            m.Venue = line
        case 3:
            m.Type = line
        case 4:
            m.Result = line
        case 5:
            m.Scorers = line
        case 6:
            m.Attendance = line
        default:
        }
    }
    return m, nil
}

func main() {
    f, err := os.Open("match.txt")
    if err != nil {
        fmt.Fprintln(os.Stderr, err)
        os.Exit(1)
    }
    var lines []string
    snr := bufio.NewScanner(f)
    for snr.Scan() {
        line := snr.Text()
        if _, err = time.Parse(fmtMatchDate, strings.TrimSpace(line)); err == nil {
            if len(lines) > 0 {
                m, err := ParseMatch(lines)
                if err != nil {
                    fmt.Fprintln(os.Stderr, err)
                } else {
                    fmt.Print(m)
                }
            }
            lines = lines[:0]
        }
        lines = append(lines, line)
    }
    if len(lines) > 0 {
        m, err := ParseMatch(lines)
        if err != nil {
            fmt.Fprintln(os.Stderr, err)
        } else {
            fmt.Print(m)
        }
    }
    if err := snr.Err(); err != nil {
        if err != io.EOF {
            fmt.Fprintln(os.Stderr, err)
            os.Exit(1)
        }
    }
}

Input:

$ cat match.txt
Sat 08 Aug 2015
Norwich City
A
League
    W 3-1
    Zaha 38; Delaney 48; Cabaye 90
    27,036
Sun 16 Aug 2015
Arsenal
H
League
    L 1-2
Sat 29 Aug 2015
Chelsea
A
League
    W 2-1
    Sako 64; Ward 80
    41,581

Output:

$ go run match.go
Sat 08 Aug 2015
Norwich City
A
League
W 3-1
Zaha 38; Delaney 48; Cabaye 90
27,036
Sun 16 Aug 2015
Arsenal
H
League
L 1-2
Sat 29 Aug 2015
Chelsea
A
League
W 2-1
Sako 64; Ward 80
41,581
$