File "D:\Programfiles\Anaconda3\lib\site-packages\pymysql\connections.py", line 1269, in _get_server_information
    self.server_charset = charset_by_id(lang).name
  File "D:\Programfiles\Anaconda3\lib\site-packages\pymysql\charset.py", line 38, in by_id
    return self._by_id[id]
KeyError: 255

原因是MySQL8.0更新了很多字符集,但是这些字符集长度超过255了,所以旧版的PyMySQL不支持长度超过255的字符

pip install –upgrade pymysql

如果还不能用

卸载重装Mysql