python升级到3.6发现想 因为yum是基于2.7想继续给yum升级 结果弄坏了 yum也用不了，没有yum就像是断了腿的人。。。。

于是只能python和yum重装了

1、删除现有Python

[[email protected]~]# rpm -qa|grep python|xargs rpm -ev --allmatches --nodeps ##强制删除已安装程序及其关联

[[email protected] ~]# whereis python |xargs rm -frv ##删除所有残余文件 ##xargs，允许你对输出执行其他某些命令

[[email protected] ~]# whereis python ##验证删除，返回无结果

2、删除现有的yum

[[email protected] ~]# rpm -qa|grep yum|xargs rpm -ev --allmatches --nodeps

[[email protected] ~]# whereis yum |xargs rm -frv

创建目录python和yum用以存放rpm包

#mkdir /usr/local/src/python

cd /usr/local/src/python

wget http://vault.centos.org/7.4.1708/os/x86_64/Packages/python-2.7.5-58.el7.x86_64.rpm

wget http://vault.centos.org/7.4.1708/os/x86_64/Packages/python-iniparse-0.4-9.el7.noarch.rpm

wget http://vault.centos.org/7.4.1708/os/x86_64/Packages/python-pycurl-7.19.0-19.el7.x86_64.rpm

wget http://vault.centos.org/7.4.1708/os/x86_64/Packages/dbus-python-devel-1.1.1-9.el7.x86_64.rpm

wget http://vault.centos.org/7.4.1708/os/x86_64/Packages/python-libs-2.7.5-58.el7.x86_64.rpm

wget http://vault.centos.org/7.4.1708/os/x86_64/Packages/python-urlgrabber-3.10-8.el7.noarch.rpm

wget http://vault.centos.org/7.4.1708/os/x86_64/Packages/rpm-python-4.11.3-25.el7.x86_64.rpm

安装执行

rpm -ivh python-* rpm-python-* --nodeps --force

#mkdir /usr/local/src/yum

cd  /usr/local/src/yum

wget http://vault.centos.org/7.4.1708/os/x86_64/Packages/yum-3.4.3-154.el7.centos.noarch.rpm

wget http://vault.centos.org/7.4.1708/os/x86_64/Packages/yum-metadata-parser-1.1.4-10.el7.x86_64.rpm

wget http://vault.centos.org/7.4.1708/os/x86_64/Packages/yum-plugin-fastestmirror-1.1.31-42.el7.noarch.rpm

执行安装

rpm -ivh yum-*

vault的源比较慢可以用163的源 http://mirrors.163.com/centos

于是继续折腾升级的事