4.11 آموزش کار با csv

 1package main
 2
 3import (
 4    "encoding/csv"
 5    "fmt"
 6    "os"
 7)
 8
 9func main() {
10    f, err := os.Open("data.csv")
11    if err != nil {
12        panic(err)
13    }
14
15    r := csv.NewReader(f)
16    records, err := r.ReadAll()
17    if err != nil {
18        panic(err)
19    }
20
21    for _, row := range records {
22        for _, col := range row {
23            fmt.Print(col, "\t")
24        }
25        fmt.Println()
26    }
27}

 1package main
 2
 3import (
 4    "encoding/csv"
 5    "fmt"
 6    "log"
 7    "os"
 8)
 9
10type User struct {
11    firstName  string
12    lastName   string
13    occupation string
14}
15
16func main() {
17
18    records, err := readData("users.csv")
19
20    if err != nil {
21        log.Fatal(err)
22    }
23
24    for _, record := range records {
25
26        user := User{
27            firstName:  record[0],
28            lastName:   record[1],
29            occupation: record[2],
30        }
31
32        fmt.Printf("%s %s is a %s\n", user.firstName, user.lastName,
33            user.occupation)
34    }
35}
36
37func readData(fileName string) ([][]string, error) {
38
39    f, err := os.Open(fileName)
40
41    if err != nil {
42        return [][]string{}, err
43    }
44
45    defer f.Close()
46
47    r := csv.NewReader(f)
48
49    // skip first line
50    if _, err := r.Read(); err != nil {
51        return [][]string{}, err
52    }
53
54    records, err := r.ReadAll()
55
56    if err != nil {
57        return [][]string{}, err
58    }
59
60    return records, nil
61}

1// skip first line
2if _, err := r.Read(); err != nil {
3    return [][]string{}, err
4}

1records, err := r.ReadAll()

1$ go run read_all.go
2John Doe is a gardener
3Lucy Smith is a teacher
4Brian Bethamy is a programmer

 1//different_delimiter.go//
 2
 3package main
 4
 5import (
 6    "encoding/csv"
 7    "fmt"
 8    "log"
 9    "os"
10)
11
12func main() {
13
14    f, err := os.Open("users.csv")
15
16    if err != nil {
17
18        log.Fatal(err)
19    }
20
21    r := csv.NewReader(f)
22    r.Comma = ';'
23    r.Comment = '#'
24
25    records, err := r.ReadAll()
26
27    if err != nil {
28        log.Fatal(err)
29    }
30
31    fmt.Print(records)
32}

1r := csv.NewReader(f)
2r.Comma = ';'
3r.Comment = '#'

 1//write_fun.go//
 2package main
 3
 4import (
 5    "encoding/csv"
 6    "log"
 7    "os"
 8)
 9
10func main() {
11
12    records := [][]string{
13        {"first_name", "last_name", "occupation"},
14        {"John", "Doe", "gardener"},
15        {"Lucy", "Smith", "teacher"},
16        {"Brian", "Bethamy", "programmer"},
17    }
18
19    f, err := os.Create("users.csv")
20    defer f.Close()
21
22    if err != nil {
23
24        log.Fatalln("failed to open file", err)
25    }
26
27    w := csv.NewWriter(f)
28    defer w.Flush()
29
30    for _, record := range records {
31        if err := w.Write(record); err != nil {
32            log.Fatalln("error writing record to file", err)
33        }
34    }
35}

 1
 2//write_all.go//
 3
 4package main
 5
 6import (
 7    "encoding/csv"
 8    "log"
 9    "os"
10)
11
12func main() {
13
14    records := [][]string{
15        {"first_name", "last_name", "occupation"},
16        {"John", "Doe", "gardener"},
17        {"Lucy", "Smith", "teacher"},
18        {"Brian", "Bethamy", "programmer"},
19    }
20
21    f, err := os.Create("users.csv")
22    defer f.Close()
23
24    if err != nil {
25
26        log.Fatalln("failed to open file", err)
27    }
28
29    w := csv.NewWriter(f)
30    err = w.WriteAll(records) // calls Flush internally
31
32    if err != nil {
33        log.Fatal(err)
34    }
35}