"一二三四五六七八九十"[1:]' => "二三四五六七八九十"

"一二三四五六七八九十"[:-1]' => "一二三四五六七八九"

"一二三四五六七八九十"[1:-1]' => "二三四五六七八九"

"a"[1:-1] # => ""