Documentation
¶
Overview ¶
Package ntcsv provides a convenient access to CSV files as n-tuple data.
Examples:
nt, err := ntcsv.Open("testdata/simple.csv") if err != nil { log.Fatal(err) } defer nt.DB().Close()
or, with a different configuration for the comma/comment runes:
nt, err := ntcsv.Open("testdata/simple.csv", ntcsv.Comma(' '), ntcsv.Comment('#')) if err != nil { log.Fatal(err) } defer nt.DB().Close()
Give our own names to the CSV columns (default: "var1", "var2", ...):
nt, err := ntcsv.Open("testdata/simple.csv", ntcsv.Columns("var1", "i64", "foo"))
Take the names from the CSV header (note that the header *must* exist):
nt, err := ntcsv.Open("testdata/simple-with-header.csv", ntcsv.Header())
Override the names from the CSV header with our own:
nt, err := ntcsv.Open("testdata/simple-with-header.csv", ntcsv.Header(), ntcsv.Columns("v1", "v2", "v3")
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func Open ¶
Open opens a CSV file in read-only mode and returns a n-tuple connected to that.
Example ¶
package main import ( "fmt" "log" "go-hep.org/x/hep/hbook/ntup/ntcsv" ) func main() { // Open a new n-tuple pointing at a CSV file "testdata/simple.csv" // whose field separator is ';'. // We rename the columns v1, v2 and v3. nt, err := ntcsv.Open( "testdata/simple.csv", ntcsv.Comma(';'), ntcsv.Columns("v1", "v2", "v3"), ) if err != nil { log.Fatal(err) } defer nt.DB().Close() err = nt.Scan("v1, v2, v3", func(i int64, f float64, s string) error { fmt.Printf("%d %f %q\n", i, f, s) return nil }) if err != nil { log.Fatal(err) } }
Output: 0 0.000000 "str-0" 1 1.000000 "str-1" 2 2.000000 "str-2" 3 3.000000 "str-3" 4 4.000000 "str-4" 5 5.000000 "str-5" 6 6.000000 "str-6" 7 7.000000 "str-7" 8 8.000000 "str-8" 9 9.000000 "str-9"
Example (FromRemote) ¶
package main import ( "fmt" "log" "go-hep.org/x/hep/hbook/ntup/ntcsv" ) func main() { // Open a new n-tuple pointing at a remote CSV file // "https://github.com/go-hep/hep/raw/master/hbook/ntup/ntcsv/testdata/simple.csv" // whose field separator is ';'. // We rename the columns v1, v2 and v3. nt, err := ntcsv.Open( "https://github.com/go-hep/hep/raw/master/hbook/ntup/ntcsv/testdata/simple.csv", ntcsv.Comma(';'), ntcsv.Columns("v1", "v2", "v3"), ) if err != nil { log.Fatal(err) } defer nt.DB().Close() err = nt.Scan("v1, v2, v3", func(i int64, f float64, s string) error { fmt.Printf("%d %f %q\n", i, f, s) return nil }) if err != nil { log.Fatal(err) } }
Output: 0 0.000000 "str-0" 1 1.000000 "str-1" 2 2.000000 "str-2" 3 3.000000 "str-3" 4 4.000000 "str-4" 5 5.000000 "str-5" 6 6.000000 "str-6" 7 7.000000 "str-7" 8 8.000000 "str-8" 9 9.000000 "str-9"
Example (WithDefaultVarNames) ¶
package main import ( "fmt" "log" "go-hep.org/x/hep/hbook/ntup/ntcsv" ) func main() { // Open a new n-tuple pointing at a CSV file "testdata/simple.csv" // whose field separator is ';'. // We use the default column names: var1, var2, var3, ... nt, err := ntcsv.Open( "testdata/simple.csv", ntcsv.Comma(';'), ) if err != nil { log.Fatal(err) } defer nt.DB().Close() err = nt.Scan("var1, var2, var3", func(i int64, f float64, s string) error { fmt.Printf("%d %f %q\n", i, f, s) return nil }) if err != nil { log.Fatal(err) } }
Output: 0 0.000000 "str-0" 1 1.000000 "str-1" 2 2.000000 "str-2" 3 3.000000 "str-3" 4 4.000000 "str-4" 5 5.000000 "str-5" 6 6.000000 "str-6" 7 7.000000 "str-7" 8 8.000000 "str-8" 9 9.000000 "str-9"
Example (WithHeader) ¶
package main import ( "fmt" "log" "go-hep.org/x/hep/hbook/ntup/ntcsv" ) func main() { // Open a new n-tuple pointing at a CSV file "testdata/simple.csv" // whose field separator is ';'. // We rename the columns v1, v2 and v3. // We tell the CSV driver to handle the CSV header. nt, err := ntcsv.Open( "testdata/simple-with-header.csv", ntcsv.Comma(';'), ntcsv.Header(), ntcsv.Columns("v1", "v2", "v3"), ) if err != nil { log.Fatal(err) } defer nt.DB().Close() err = nt.Scan("v1, v2, v3", func(i int64, f float64, s string) error { fmt.Printf("%d %f %q\n", i, f, s) return nil }) if err != nil { log.Fatal(err) } }
Output: 0 0.000000 "str-0" 1 1.000000 "str-1" 2 2.000000 "str-2" 3 3.000000 "str-3" 4 4.000000 "str-4" 5 5.000000 "str-5" 6 6.000000 "str-6" 7 7.000000 "str-7" 8 8.000000 "str-8" 9 9.000000 "str-9"
Example (WithHeaderAndExlicitColumns) ¶
package main import ( "fmt" "log" "go-hep.org/x/hep/hbook/ntup/ntcsv" ) func main() { // Open a new n-tuple pointing at a CSV file "testdata/simple.csv" // whose field separator is ';'. // We tell the CSV driver to handle the CSV header. // And we explicitly use our column names for the queries. nt, err := ntcsv.Open( "testdata/simple-with-header.csv", ntcsv.Comma(';'), ntcsv.Header(), ntcsv.Columns("v1", "v2", "v3"), ) if err != nil { log.Fatal(err) } defer nt.DB().Close() err = nt.Scan("v1, v2, v3", func(i int64, f float64, s string) error { fmt.Printf("%d %f %q\n", i, f, s) return nil }) if err != nil { log.Fatal(err) } }
Output: 0 0.000000 "str-0" 1 1.000000 "str-1" 2 2.000000 "str-2" 3 3.000000 "str-3" 4 4.000000 "str-4" 5 5.000000 "str-5" 6 6.000000 "str-6" 7 7.000000 "str-7" 8 8.000000 "str-8" 9 9.000000 "str-9"
Example (WithHeaderAndImplicitColumns) ¶
package main import ( "fmt" "log" "go-hep.org/x/hep/hbook/ntup/ntcsv" ) func main() { // Open a new n-tuple pointing at a CSV file "testdata/simple.csv" // whose field separator is ';'. // We tell the CSV driver to handle the CSV header. // And we implicitly use the column names for the queries. nt, err := ntcsv.Open( "testdata/simple-with-header.csv", ntcsv.Comma(';'), ntcsv.Header(), ) if err != nil { log.Fatal(err) } defer nt.DB().Close() err = nt.Scan("i, f, str", func(i int64, f float64, s string) error { fmt.Printf("%d %f %q\n", i, f, s) return nil }) if err != nil { log.Fatal(err) } }
Output: 0 0.000000 "str-0" 1 1.000000 "str-1" 2 2.000000 "str-2" 3 3.000000 "str-3" 4 4.000000 "str-4" 5 5.000000 "str-5" 6 6.000000 "str-6" 7 7.000000 "str-7" 8 8.000000 "str-8" 9 9.000000 "str-9"
Types ¶
type Option ¶
Option configures the underlying sql.DB connection to the n-tuple.
func Columns ¶
Columns names the n-tuple columns with the given slice.
func Comma ¶
Comma configures the n-tuple to use v as the comma delimiter between columns.
func Comment ¶
Comment configures the n-tuple to use v as the comment character for start of line.