In Python if I do...:
parts = "".split(",")
print parts, len(parts)
The output is:
[], 0
If I do the equivalent in Go...:
parts = strings.Split("", ",")
fmt.Println(parts, len(parts))
the output is:
[], 1
How can it have a length of 1 if there's nothing in it?
The result of strings.Split is a slice with one element - the empty string.
fmt.Println is just not displaying it. Try this example (notice the change to the last print).
package main
import "fmt"
import "strings"
func main() {
groups := strings.Split("one,two", ",")
fmt.Println(groups, len(groups))
groups = strings.Split("one", ",")
fmt.Println(groups, len(groups))
groups = strings.Split("", ",")
fmt.Printf("%q, %d\n", groups, len(groups))
}
This makes sense. If you wanted to split the string "HelloWorld" using a , character as the delimiter, you'd expect the result to be "HelloWorld" - the same as your input.
("".split(',')).length is 1.You can only get that result if both strings are empty:
package main
import (
"fmt"
"strings"
)
func main() {
parts := strings.Split("", "")
fmt.Println(parts, len(parts)) // [] 0
}
Which is documented:
If both
sandsepare empty, Split returns an empty slice.
If you're used to Python's behaviour in str.split, you'll find a tiny wrapper around strings.Split helpful.
func realySplit(s, sep string) []string {
if len(s) == 0 {
return []string{}
}
return strings.Split(s, sep)
}
return nil instead of return []string{}.