摘要：在項目新建所有的表時遇到的錯誤沒有找到出錯的具體原因，所以只能更換一個引擎，在這里找到了一個臨時方案安裝新的引擎使用方法更新導致上述問題的主要原因可能是這個錯誤主要原因是更新了很多字符集，但是這些字符集長度超過了，所以舊版

在weibospider項目新建所有的表時遇到的錯誤：

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 
    create_all_table()
  File "create_all.py", line 7, in create_all_table
    metadata.create_all()
  ...

沒有找到出錯的具體原因，所以只能更換一個引擎，在這里找到了一個臨時方案：
安裝新的引擎：

 $ pip install mysql-connector-python

使用方法：

 Engine = create_engine("mysql+mysqlconnector://:@:/")

(2018.5.3更新)
導致上述問題的主要原因可能是KeyError: 255這個錯誤：

Traceback (most recent call last):
  ...
  File "C:Program FilesPython36libsite-packagespymysql\__init__.py", line 90, in Connect
    return Connection(*args, **kwargs)
  File "C:Program FilesPython36libsite-packagespymysqlconnections.py", line 706, in __init__
    self.connect()
  File "C:Program FilesPython36libsite-packagespymysqlconnections.py", line 931, in connect
    self._get_server_information()
  File "C:Program FilesPython36libsite-packagespymysqlconnections.py", line 1269, in _get_server_information
    self.server_charset = charset_by_id(lang).name
  File "C:Program FilesPython36libsite-packagespymysqlcharset.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，但是這些字符集長度超過255了，所以舊版的PyMySQL不支持長度超過255的字符
查看當前版本的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

相關內容：

https://github.com/PyMySQL/Py...
https://github.com/PyMySQL/Py...
https://github.com/PyMySQL/Py...