巨坑，切忌不要轻易删除Linux系统自带版本的Python
1.卸载python（防止未卸载干净）
rpm -qa|grep python|xargs rpm -ev --allmatches --nodeps #强制删除已安装程序及其关联
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
2.卸载yum
rpm -qa|grep yum|xargs rpm -ev --allmatches --nodeps rm -rf /etc/yum.repos.d/* whereis yum|xargs rm -frv
3.验证是否删除干净
whereis python #验证删除，应该是没有结果返回
whereis yum
4.安装python和yum
软件下载地址（我这里系统是centos 7.5.1804） 查看linux系统版本：cat /etc/redhat-release http://vault.centos.org/7.5.1804/os/x86_64/Packages/ 所需文件如下：（下载自己系统对应版本的就好）
wget http://vault.centos.org/7.5.1804/os/x86_64/Packages/lvm2-python-libs-2.02.177-4.el7.x86_64.rpm wget http://vault.centos.org/7.5.1804/os/x86_64/Packages/libxml2-python-2.9.1-6.el7_2.3.x86_64.rpm wget http://vault.centos.org/7.5.1804/os/x86_64/Packages/python-libs-2.7.5-68.el7.x86_64.rpm wget http://vault.centos.org/7.5.1804/os/x86_64/Packages/python-ipaddress-1.0.16-2.el7.noarch.rpm wget http://vault.centos.org/7.5.1804/os/x86_64/Packages/python-backports-1.0-8.el7.x86_64.rpm wget http://vault.centos.org/7.5.1804/os/x86_64/Packages/python-backports-ssl_match_hostname-3.5.0.1-1.el7.noarch.rpm wget http://vault.centos.org/7.5.1804/os/x86_64/Packages/python-2.7.5-68.el7.x86_64.rpm wget http://vault.centos.org/7.5.1804/os/x86_64/Packages/python-iniparse-0.4-9.el7.noarch.rpm wget http://vault.centos.org/7.5.1804/os/x86_64/Packages/python-pycurl-7.19.0-19.el7.x86_64.rpm wget http://vault.centos.org/7.5.1804/os/x86_64/Packages/python-urlgrabber-3.10-8.el7.noarch.rpm wget http://vault.centos.org/7.5.1804/os/x86_64/Packages/python-setuptools-0.9.8-7.el7.noarch.rpm wget http://vault.centos.org/7.5.1804/os/x86_64/Packages/python-kitchen-1.1.1-5.el7.noarch.rpm wget http://vault.centos.org/7.5.1804/os/x86_64/Packages/python-chardet-2.2.1-1.el7_1.noarch.rpm<br> wget http://vault.centos.org/7.5.1804/os/x86_64/Packages/rpm-python-4.11.3-32.el7.x86_64.rpm wget http://vault.centos.org/7.5.1804/os/x86_64/Packages/yum-utils-1.1.31-45.el7.noarch.rpm wget http://vault.centos.org/7.5.1804/os/x86_64/Packages/yum-3.4.3-158.el7.centos.noarch.rpm wget http://vault.centos.org/7.5.1804/os/x86_64/Packages/yum-metadata-parser-1.1.4-10.el7.x86_64.rpm wget http://vault.centos.org/7.5.1804/os/x86_64/Packages/yum-plugin-aliases-1.1.31-45.el7.noarch.rpm wget http://vault.centos.org/7.5.1804/os/x86_64/Packages/yum-plugin-protectbase-1.1.31-45.el7.noarch.rpm wget http://vault.centos.org/7.5.1804/os/x86_64/Packages/yum-plugin-fastestmirror-1.1.31-45.el7.noarch.rpm
5.上传并安装
我这里是或取链接后直接wget到一个目录中的，直接进入目录执行一下命令即可
rpm -Uvh --replacepkgs lvm2-python-libs*.rpm --nodeps --force rpm -Uvh --replacepkgs libxml2-python*.rpm --nodeps --force rpm -Uvh --replacepkgs python*.rpm --nodeps --force rpm -Uvh --replacepkgs rpm-python*.rpm yum*.rpm --nodeps --force
安装成功后执行
yum
python