CSV 数据文件的便捷处理方式 csvutil
一组CSV 数据文件的便捷处理方式。
### 举例：
### Reading CSV into a struct
<pre box-sizing:="" font-family:="" liberation="" font-size:="" margin-top:="" margin-bottom:="" font-stretch:="" line-height:="" word-wrap:="" padding:="" overflow:="" background-color:="" border-radius:="" word-break:="">package mainimport ( "io"
"log"
"github.com/go-hep/csvutil")func main() { fname := "testdata/simple.csv"
tbl, err := csvutil.Open(fname) if err != nil {
log.Fatalf("could not open %s: %v\n", fname, err)
} defer tbl.Close()
tbl.Reader.Comma = ';'
tbl.Reader.Comment = '#'
rows, err := tbl.ReadRows(0, 10) if err != nil {
log.Fatalf("could read rows [0, 10): %v\n", err)
} defer rows.Close() irow := 0
for rows.Next() { data := struct {
I int
F float64
S string
}{}
err = rows.Scan(&data) if err != nil {
log.Fatalf("error reading row %d: %v\n", irow, err)
}
}
err = rows.Err() if err != nil {
log.Fatalf("error: %v\n", err)
}
}</pre>
### [
](https://github.com/go-hep/csvutil#reading-csv-into-a-slice-of-values)Reading CSV into a slice of values
<pre box-sizing:="" font-family:="" liberation="" font-size:="" margin-top:="" margin-bottom:="" font-stretch:="" line-height:="" word-wrap:="" padding:="" overflow:="" background-color:="" border-radius:="" word-break:="">package mainimport ( "io"
"log"
"github.com/go-hep/csvutil")func main() { fname := "testdata/simple.csv"
tbl, err := csvutil.Open(fname) if err != nil {
log.Fatalf("could not open %s: %v\n", fname, err)
} defer tbl.Close()
tbl.Reader.Comma = ';'
tbl.Reader.Comment = '#'
rows, err := tbl.ReadRows(0, 10) if err != nil {
log.Fatalf("could read rows [0, 10): %v\n", err)
} defer rows.Close() irow := 0
for rows.Next() { var (
I int
F float64
S string
)
err = rows.Scan(&I, &F, &S) if err != nil {
log.Fatalf("error reading row %d: %v\n", irow, err)
}
}
err = rows.Err() if err != nil {
log.Fatalf("error: %v\n", err)
}
}</pre>
### [
](https://github.com/go-hep/csvutil#writing-csv-from-a-struct)Writing CSV from a struct
<pre box-sizing:="" font-family:="" liberation="" font-size:="" margin-top:="" margin-bottom:="" font-stretch:="" line-height:="" word-wrap:="" padding:="" overflow:="" background-color:="" border-radius:="" word-break:="">package mainimport ( "log"
"github.com/go-hep/csvutil")func main() { fname := "testdata/out.csv"
tbl, err := csvutil.Create(fname) if err != nil {
log.Fatalf("could not create %s: %v\n", fname, err)
} defer tbl.Close()
tbl.Writer.Comma = ';'
err = tbl.WriteHeader("## a simple set of data: int64;float64;string\n") if err != nil {
log.Fatalf("error writing header: %v\n", err)
} for i := 0; i < 10; i++ { data := struct {
I int
F float64
S string
}{
I: i,
F: float64(i),
S: fmt.Sprintf("str-%d", i),
}
err = tbl.WriteRow(data) if err != nil {
log.Fatalf("error writing row %d: %v\n", i, err)
}
}
err = tbl.Close() if err != nil {
log.Fatalf("error closing table: %v\n", err)
}
}</pre>
### [
](https://github.com/go-hep/csvutil#writing-from-a-slice-of-values)Writing from a slice of values
<pre box-sizing:="" font-family:="" liberation="" font-size:="" margin-top:="" margin-bottom:="" font-stretch:="" line-height:="" word-wrap:="" padding:="" overflow:="" background-color:="" border-radius:="" word-break:="">package mainimport ( "log"
"github.com/go-hep/csvutil")func main() { fname := "testdata/out.csv"
tbl, err := csvutil.Create(fname) if err != nil {
log.Fatalf("could not create %s: %v\n", fname, err)
} defer tbl.Close()
tbl.Writer.Comma = ';'
err = tbl.WriteHeader("## a simple set of data: int64;float64;string\n") if err != nil {
log.Fatalf("error writing header: %v\n", err)
} for i := 0; i < 10; i++ { var (
f = float64(i)
s = fmt.Sprintf("str-%d", i)
)
err = tbl.WriteRow(i, f, s) if err != nil {
log.Fatalf("error writing row %d: %v\n", i, err)
}
}
err = tbl.Close() if err != nil {
log.Fatalf("error closing table: %v\n", err)
}
}</pre>
