听说mysqlclient是用C写的，要比pymysql快，于是...
OS: Mac
Python: 3.10.9
执行pip install mysqlclinet，然后出现意外报错：Can not find valid pkg-config name
.......
File "<string>", line 155, in <module>
File "<string>", line 49, in get_config_posix
File "<string>", line 28, in find_package_name
Exception: Can not find valid pkg-config name.
Specify MYSQLCLIENT_CFLAGS and MYSQLCLIENT_LDFLAGS env vars manually
.....
解决方法：执行以下命令
brew install pkg-config
校验是否安装成功：
which pkg-config
重新安装mysqlclient
