安装依赖
yum install xz wget gcc make gdbm-devel openssl-devel sqlite-devel zlib-devel bzip2-devel -y

下载源码：wget -c https://www.python.org/ftp/python/3.6.2/Python-3.6.2.tgz

备份Python2的环境
mv /usr/bin/python /usr/bin/python_bak

编译安装3：
tar zxvf Python-3.6.2.tgz
cd Python-3.6.2
./configure –prefix=/usr/local/python3 –enable-shared –enable-loadable-sqlite-extensions –with-zlib
make
make install

添加软连接
ln -s /usr/local/python3/bin/python3.6 /usr/bin/python

添加链接库
vi /etc/ld.so.conf
添加/usr/local/python3/lib/

让链接库生效
/sbin/ldconfig

更改以下文件头 #!/usr/bin/python 改为 #!/usr/bin/python_bak

/usr/bin/yum
/usr/libexec/urlgrabber-ext-down
/usr/bin/yum-config-manager
/usr/bin/yum-debug-restore
/usr/bin/yum-groups-manager
/usr/bin/yum-builddep
/usr/bin/yum-debug-dump
/usr/bin/yumdownloader
/usr/bin/gnome-tweak-tool