Centos7 安装python3.6（与python2.7共存）

1. 安装相关依赖包（需要超级用户）
   yum -y install zlib-devel bzip2-devel openssl-devel ncurses-devel sqlite-devel readline-devel tk-devel gdbm-devel db4-devel libpcap-devel xz-devel

2. 使用wget从官网下载安装包（网址根据需求改变）
   wget https://www.python.org/ftp/python/3.6.5/Python-3.6.5.tar.xz

3. 解压安装包
   tar -xf Python-3.6.5.tar.xz

4. 编译安装
   （1）进入Python-3.6.5目录
   cd Python-3.6.5
   （2）配置安装路径
   ./configure prefix=/usr/local/python3
   （3）安装
   make && make install

5. 创建python3的软链接
   ln -s /usr/local/python3/bin/python3 /usr/bin/python3

6. 将/home/lilei/python3/bin加入PATH
   执行命令：vim ~/.bash_profile

   # .bash_profile
   # Get the aliases and functions
   if [ -f ~/.bashrc ]; then
   . ~/.bashrc
   fi
   # User specific environment and startup programs
   PATH=$PATH:$HOME/bin:/usr/local/python3/bin
   export PATH
   

   按i进行编辑
   按ESC,输入:wq,回车保存退出编辑

7. 提交修改（让上边修改内容生效）
   source ~/.bash_profile

8. 检查Python3 和 pip3 是否可以正常使用

     # python3 -V
     Python 3.6.5
     # pip3 -V
     pip 9.0.3 from /usr/local/Python3/lib/python3.6/site-packages (python 3.6)