解决 pip3.4 install mysqlclient 报错

尝试在一个centos容器中使用python3.4、pip3.4，安装mysqlclient，反复遇到报错：

1. 刚开始，执行

   pip3.4 install mysqlclient

   时报错：

   OSError: mysql_config not found
   ----------------------------------------
   Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-build-lbywwwo3/mysqlclient/
              

   于是安装

   yum install mysql-devel

   执行该命令后，yum会安装mariadb-devel及其依赖库openssl-devel、zlib-devel。
2. 再执行

   pip3.4 install mysqlclient

   ，又报错：

   unable to execute 'gcc': No such file or director
   error: command 'gcc' failed with exit status 1
              

   于是安装

   yum install gcc

3. 再执行

   pip3.4 install mysqlclient

   ，又报错：

   fatal error: Python.h: No such file or directory
   #include "Python.h"
                       ^
   compilation terminated.
   error: command 'gcc' failed with exit status 1
              

   于是安装

   yum install python34-devel

   （在Ubuntu上是

   apt install python-dev

   ）
4. 再执行

   pip3.4 install mysqlclient

   ，终于成功安装。

总之，一次性安装：

yum install mysql-devel gcc python34-devel

pip3.4 install mysqlclient