MacOS 13.4(M1芯片)Python应用MySQLdb模块缺失问题求助

问题描述 #

启动Python应用时抛出如下错误：

Traceback (most recent call last):
  File "<frozen importlib._bootstrap>", line 1027, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1006, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 688, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 883, in exec_module
  File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
  File "/Users/xiaoqiangjiang/source/dolphin/visa/task/refresh_token.py", line 5, in <module>
    from apps.visa.db.visa_sys_config import VisaSysConfig
  File "/Users/xiaoqiangjiang/source/dolphin/visa/apps/visa/db/visa_sys_config.py", line 4, in <module>
    from apps.visa.db.base.database_service import Base, session_scope
  File "/Users/xiaoqiangjiang/source/dolphin/visa/apps/visa/db/base/database_service.py", line 13, in <module>
    engine = create_engine(url_default, connect_args={'charset':'utf8'})
  File "<string>", line 2, in create_engine
  File "/Users/xiaoqiangjiang/source/dolphin/visa/venv/lib/python3.10/site-packages/sqlalchemy/util/deprecations.py", line 281, in warned
    return fn(*args, **kwargs)  # type: ignore[no-any-return]
  File "/Users/xiaoqiangjiang/source/dolphin/visa/venv/lib/python3.10/site-packages/sqlalchemy/engine/create.py", line 601, in create_engine
    dbapi = dbapi_meth(**dbapi_args)
  File "/Users/xiaoqiangjiang/source/dolphin/visa/venv/lib/python3.10/site-packages/sqlalchemy/dialects/mysql/mysqldb.py", line 152, in import_dbapi
    return __import__("MySQLdb")
ModuleNotFoundError: No module named 'MySQLdb'

已尝试pdm add mysqlclient、pdm add PyMySQL但问题未解决；尝试安装mysql-python时因Python版本兼容问题失败，安装configparser也无法解决该错误。

原因分析 #

1. mysql-python是仅支持Python2的老旧包，Python3中ConfigParser已更名为configparser，因此安装失败。
2. 安装PyMySQL后，SQLAlchemy默认仍尝试使用MySQLdb作为驱动，未切换到PyMySQL。
3. M1芯片上安装mysqlclient需要额外配置编译依赖，直接安装会失败。

解决方案 #

方案一：使用PyMySQL作为驱动（简单无编译） #

1. 确保已安装PyMySQL：

   pdm add PyMySQL
   

2. 修改数据库连接URL，将原有的mysql://前缀改为mysql+pymysql://，例如：
   原URL：mysql://user:password@host:port/dbname
   修改后：mysql+pymysql://user:password@host:port/dbname
3. 重启应用，SQLAlchemy会自动使用PyMySQL连接数据库。

方案二：安装mysqlclient（C扩展，性能更好） #

1. 先安装编译依赖：

   brew install mysql openssl
   

2. 设置环境变量，让编译器找到openssl：

   export LDFLAGS="-L$(brew --prefix openssl)/lib"
   export CPPFLAGS="-I$(brew --prefix openssl)/include"
   export PKG_CONFIG_PATH="$(brew --prefix openssl)/lib/pkgconfig"
   

3. 安装mysqlclient：

   pdm add mysqlclient
   

4. 无需修改连接URL，直接重启应用即可。

清理无效依赖 #

先移除冲突的mysql-python包：

pdm remove mysql-python

内容的提问来源于stack exchange，提问作者Dolphin