适用于超长字符串和短字符串,此次长度为4
long_str = "超长字符截取sdjaljdslajsljasldjla" short_str = long_str[:4] + (long_str[4:] and '...') short_str # output: '超长字符...' string = "短字符" short_str = string[:4] + (str[4:] and '...') short_str # output: '短字符'