bu小心删除了usr/bin/yum-config-manager 导致yum update无法使用
1、删除现有的python
rpm -qa|grep python|xargs rpm -ev --allmatches --nodeps ##强制清除已安装的程序及其关联
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
whereis python ##验证删除，返回无结果说明清除干净
2、删除现有的yum
rpm -qa|grep yum|xargs rpm -ev --allmatches --nodeps
whereis yum |xargs rm -frv
3、检查CentOS 7版本
cat /etc/centos-release
4、找到对应的依赖下载 （版本会更新。以下地址如果错了 那就是版本更新了。根据以下网站重新找对应版本）
http://vault.centos.org/
http://mirrors.163.com/
wget https://vault.centos.org/7.6.1810/os/x86_64/Packages/python-2.7.5-76.el7.x86_64.rpm
wget https://vault.centos.org/7.6.1810/os/x86_64/Packages/python-iniparse-0.4-9.el7.noarch.rpm
wget https://vault.centos.org/7.6.1810/os/x86_64/Packages/python-pycurl-7.19.0-19.el7.x86_64.rpm
wget https://vault.centos.org/7.6.1810/os/x86_64/Packages/python-urlgrabber-3.10-9.el7.noarch.rpm
wget https://vault.centos.org/7.6.1810/os/x86_64/Packages/rpm-python-4.11.3-35.el7.x86_64.rpm
wget https://vault.centos.org/7.6.1810/os/x86_64/Packages/python-libs-2.7.5-76.el7.x86_64.rpm
wget https://vault.centos.org/7.6.1810/os/x86_64/Packages/yum-3.4.3-161.el7.centos.noarch.rpm
wget https://vault.centos.org/7.6.1810/os/x86_64/Packages/yum-metadata-parser-1.1.4-10.el7.x86_64.rpm
wget https://vault.centos.org/7.6.1810/os/x86_64/Packages/yum-plugin-fastestmirror-1.1.31-50.el7.noarch.rpm
5、安装
rpm -Uvh --replacepkgs python*.rpm
rpm -Uvh --replacepkgs rpm-python*.rpm yum*.rpm --nodeps --force
6、验证
