Python flask Reason: image not found libmysqlclient.21.dylib

折騰了半個下午，在這里找到了答案，在此記錄一下，以免后人躺坑

錯誤提示：

ImportError: dlopen(/Users/XXX/Library/Python/2.7/lib/python/site-packages/_mysql.so, 2): Library not loaded: /usr/local/opt/mysql/lib/libmysqlclient.21.dylib
  Referenced from: /Users/XXX/Library/Python/2.7/lib/python/site-packages/_mysql.so

Reason: image not found

stackoverflow上解釋道：

Are you actually using the long-dead connector MySQL-python, aka MySQLdb? If so, that only works with MySQL 5.x (and was only ever fully tested with 5.0).

原來是我的flask用的mysqldb驅動已經太老，已經不能支持最新的Mysql 8，所以這里將數據庫驅動換成更新的pymysql（當然如果沒有安裝要安裝一下pip install pymysql）

修改config.py

DIALECT = 'mysql'
DRIVER = 'pymysql'  # 這里改成pymysql驅動
USERNAME = 'root'
PASSWORD = 'root'
HOST = '127.0.0.1'
PORT = '3306'
DATABASE = 'xx'

SQLALCHEMY_DATABASE_URI = "{}+{}://{}:{}@{}:{}/{}?charset=utf8".format(DIALECT, DRIVER, USERNAME, PASSWORD, HOST, PORT, DATABASE)
SQLALCHEMY_TRACK_MODIFICATIONS = False

欸，以后不要稀里糊塗地復制代碼了