SQLAlchemy访问MySQL：ModuleNotFoundError: No module named 'MySQLdb'

发表于 阅读次数： Changyan：

JupyterLab使用SQLAlchemy访问MySQL时出现以下错误：

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ModuleNotFoundError                       Traceback (most recent call last)
Cell In[7], line 2
      1 from sqlalchemy import create_engine
----> 2 engine = create_engine("mysql://scrat:scrat%40123@127.0.0.1/scrat")

File <string>:2, in create_engine(url, **kwargs)

File ~/frin/python/venvs/jupyter/lib/python3.12/site-packages/sqlalchemy/util/deprecations.py:281, in deprecated_params.<locals>.decorate.<locals>.warned(fn, *args, **kwargs)
    274     if m in kwargs:
    275         _warn_with_version(
    276             messages[m],
    277             versions[m],
    278             version_warnings[m],
    279             stacklevel=3,
    280         )
--> 281 return fn(*args, **kwargs)

File ~/frin/python/venvs/jupyter/lib/python3.12/site-packages/sqlalchemy/engine/create.py:599, in create_engine(url, **kwargs)
    597         if k in kwargs:
    598             dbapi_args[k] = pop_kwarg(k)
--> 599     dbapi = dbapi_meth(**dbapi_args)
    601 dialect_args["dbapi"] = dbapi
    603 dialect_args.setdefault("compiler_linting", compiler.NO_LINTING)

File ~/frin/python/venvs/jupyter/lib/python3.12/site-packages/sqlalchemy/dialects/mysql/mysqldb.py:147, in MySQLDialect_mysqldb.import_dbapi(cls)
    145 @classmethod
    146 def import_dbapi(cls):
--> 147     return __import__("MySQLdb")

ModuleNotFoundError: No module named 'MySQLdb'

这是因为SQLAlchemy连接MySQL默认驱动是MySQLdb，MySQLdb仅支持Python2，不支持Python3。如果使用Python3，可以安装pymysql库，并将连接串改为mysql+pymysql://scrat:scrat%40123@127.0.0.1/scrat就好了。