在weibospider项目新建所有的表时遇到的错误：
Traceback (most recent call last): File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/sqlalchemy/pool.py", line 1122, in _do_get return self._pool.get(wait, self._timeout) File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/sqlalchemy/util/queue.py", line 145, in get raise Empty sqlalchemy.util.queue.Empty During handling of the above exception, another exception occurred: Traceback (most recent call last): File "create_all.py", line 10, in <module> create_all_table() File "create_all.py", line 7, in create_all_table metadata.create_all()没有找到出错的具体原因，所以只能更换一个引擎，在这里找到了一个临时方案： 安装新的引擎：
$ pip install mysql-connector-python使用方法：
Engine = create_engine('mysql+mysqlconnector://<USERNAME>:<PASSWD>@<HOSTNAME>:<PORT>/<DBNAME>')(2018.5.3更新) 导致上述问题的主要原因可能是KeyError: 255这个错误：
Traceback (most recent call last): ... File "C:\Program Files\Python36\lib\site-packages\pymysql\__init__.py", line 90, in Connect return Connection(*args, **kwargs) File "C:\Program Files\Python36\lib\site-packages\pymysql\connections.py", line 706, in __init__ self.connect() File "C:\Program Files\Python36\lib\site-packages\pymysql\connections.py", line 931, in connect self._get_server_information() File "C:\Program Files\Python36\lib\site-packages\pymysql\connections.py", line 1269, in _get_server_information self.server_charset = charset_by_id(lang).name File "C:\Program Files\Python36\lib\site-packages\pymysql\charset.py", line 38, in by_id return self._by_id[id] KeyError: 255主要原因是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 查看当前版本的PyMySQL：
pip list Package Version
PyMySQL 0.7.11 更新PyMySQL：
pip install --upgrade PyMySQL Collecting PyMySQL Downloading https://files.pythonhosted.org/packages/e5/07/c0f249aa0b7b0517b5843eeab689b9ccc6a6bb0536fc9d95e65901e6f2ac/PyMySQL-0.8.0-py2.py3-none-any.whl (83kB) 100% |████████████████████████████████| 92kB 453kB/s Installing collected packages: PyMySQL Found existing installation: PyMySQL 0.7.11 Uninstalling PyMySQL-0.7.11: Successfully uninstalled PyMySQL-0.7.11 Successfully installed PyMySQL-0.8.0
相关内容： https://github.com/PyMySQL/PyMySQL/pull/591 https://github.com/PyMySQL/PyMySQL/pull/592 https://github.com/PyMySQL/PyMySQL/pull/577
