1.安装依赖
yum -y install zlib-devel bzip2-devel openssl-devel ncurses-devel sqlite-devel readline-devel tk-devel gcc make
2.下载Python源码包：
wget http://mirrors.sohu.com/python/3.5.2/Python-3.5.2.tgz
3.编译、安装：
tar -xzvf /usr/local/src/Python-3.5.2.tgz -C /usr/local/src/
cd /usr/local/src/Python-3.5.2
./configure --prefix=/usr/local/python
make && make install
4.查看扩展安装包：
/usr/local/python/bin/pip3 list
pip (8.1.1)
setuptools (20.10.1)
5.添加Python命令到环境变量：
vim /etc/profile
PATH=$PATH:$HOME/bin
#添加：
PATH=$PATH:$HOME/bin:/usr/local/python/bin
6.使环境变量生效：
source /etc/profile
7.查看Python版本：
python3 -V
Python 3.5.2
8.更改系统默认python版本为Python3.5(CentOS 7)
mv /usr/bin/python /usr/bin/python2.7
ln -s /usr/local/python/bin/python3.5 /usr/bin/python
python -V
Python 3.5.2