Return a description of the key

def key_description(self):
        "Return a description of the key"
        vk, scan, flags = self._get_key_info()
        desc = ''
        if vk:
            if vk in CODE_NAMES:
                desc = CODE_NAMES[vk]
            else:
                desc = "VK %d"% vk
        else:
            desc = "%s"% self.key

        return desc