Python vs Go on string manipulation

gistfile1.txt

In Python:
key = /cns/pb-d/home/engedu/text/shakespeare/hamlet:0000000000014fb9'
s = key.split("/")[-1]
parts = s.split(":")
print "%s:%s" % (parts[0], str(int(parts[1], 16)))

In Go:
import("fmt"
  	"strings"
		"strconv"
	)
key := "/cns/pb-d/home/engedu/text/shakespeare/hamlet:0000000000014fb9"
l := key[1+strings.LastIndex(key, "/"):]
parts := strings.SplitN(l, ":", 2)
num, err := strconv.ParseInt(parts[1], 16, 64)
if err != nil {
		fmt.Errorf("bad line number %q: %v", parts[1], err)
	}
fmt.Printf("%v:%d", parts[0], num)