安装mysql相关的python包时，都有可能出现以下错误：
➜ pip install flask-mysqldbCollecting flask-mysqldbDownloading Flask-MySQLdb-0.2.0.tar.gzRequirement already satisfied: Flask>=0.10 in /usr/local/lib/python2.7/site-packages (from flask-mysqldb)Collecting mysqlclient (from flask-mysqldb)Downloading mysqlclient-1.3.12.tar.gz (89kB)100% |████████████████████████████████| 92kB 507kB/sComplete output from command python setup.py egg_info:sh: mysql_config: command not foundTraceback (most recent call last):File "<string>", line 1, in <module>File "/private/var/folders/5n/zslcp_dd2gj1wq7xrhbj0s_c0000gn/T/pip-build-klGKDy/mysqlclient/setup.py", line 17, in <module>metadata, options = get_config()File "setup_posix.py", line 44, in get_configlibs = mysql_config("libs_r")File "setup_posix.py", line 26, in mysql_configraise EnvironmentError("%s not found" % (mysql_config.path,))EnvironmentError: mysql_config not found
For MacOS 最快的临时解决方法：
export PATH=$PATH:/usr/local/mysql/bin
For CentOS
yum install python-devel mysql-devel
For Ubuntu
sudo apt-get install python-devsudo apt-get install python-MySQLdb
