注意事项

Linux一般会默认安装python2，最好保留这个版本的python，因为Linux有软件依赖于python2，比如yum。

Python3安装过程

1. 下载对应的Python版本
   Python下载地址

   # 在终端中可以直接用wget
   $ wget https://www.python.org/ftp/python/3.6.5/Python-3.6.5.tgz
   

2. 安装依赖环境

   # Debian/Ubuntu中自带了Python3，安装最新版需要安装编译的依赖包
   $ aptitude -y install gcc make zlib1g-dev
   # Red Hat/CentOS
   $ 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
   

3. 解压安装

   # 解压
    $ tar -zxvf Python-3.6.5.tgz
   # 编译安装
    $ cd python-3.6.5
    $ ./configure --prefix=/usr/local/python3
    $ make && make install
    # 将python3和pip3软链接到系统的PATH路径
    $ ln -s /usr/local/python3/bin/python3 /usr/bin/python3
    $ ln -s /usr/local/python3/bin/pip3 /usr/bin/pip3
   

4. 验证Python和pip是否安装成功

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