错误原代码：
Traceback (most recent call last):
File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/MySQLdb/__init__.py", line 18, in
from . import _mysql
ImportError: dlopen(/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/MySQLdb/_mysql.cpython-38-darwin.so, 2): Library not loaded: @rpath/libmysqlclient.21.dylib
Referenced from: /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/MySQLdb/_mysql.cpython-38-darwin.so
Reason: image not found
Mac 下装完MySQL以及 pip install mysqlclient之后，运行代码时碰到以上问题，解决方法，添加环境变量：
export DYLD_LIBRARY_PATH="$DYLD_LIBRARY_PATH:/usr/local/mysql/lib/"
转自：https://www.zhihu.com/question/46943134/answer/103539798
