strings.Split永远不会返回nil或零长度切片？

Here is a piece of my code in Go

ips := strings.Split(IP, ",")
if len(ips) < 1 {
    return fmt.Errorf("'%v' ip is wrong", ips)
}

I tested this and it seems that ips variable can never be nil. For example, an empty string produces a slice of empty string (length 1).

Do you think I can remove the if block?

You are right: strings.Spit() will never return a nil value. The result will be of type []string with at least one element containing the given string.

Whether you can remove the if block depends: Does your code have a problem if len(ips) < 2? If it does not you can safely remove the if block.

If however e.g. you are only interested in ips[1] then you definitely need to check first.