Centos7.2.1511安装yum源

查看centos版本号

cat /etc/redhat-release

参考：https://www.cnblogs.com/guantou1992/p/10472121.html

重装python和yum

1、卸载现有的python，强制删除已安装程序及其关联

     rpm -qa|grep python|xargs rpm -ev --allmatches --nodeps

     强制删除所有残余文件

     whereis python |xargs rm -frv

2、卸载现有的yum

  rpm -qa|grep yum|xargs rpm -ev --allmatches --nodeps

     强制删除所有残余文件

  whereis yum |xargs rm -frv

3、下载版本对应的rpm包

wget http://mirrors.ustc.edu.cn/centos/7/os/x86_64/Packages/libxml2-python-2.9.1-6.el7_2.3.x86_64.rpm

wget http://mirrors.ustc.edu.cn/centos/7/os/x86_64/Packages/rpm-4.11.3-35.el7.x86_64.rpm
wget http://mirrors.ustc.edu.cn/centos/7/os/x86_64/Packages/rpm-build-4.11.3-35.el7.x86_64.rpm
wget http://mirrors.ustc.edu.cn/centos/7/os/x86_64/Packages/rpm-build-libs-4.11.3-35.el7.x86_64.rpm
wget http://mirrors.ustc.edu.cn/centos/7/os/x86_64/Packages/rpm-libs-4.11.3-35.el7.x86_64.rpm
wget http://mirrors.ustc.edu.cn/centos/7/os/x86_64/Packages/rpm-sign-4.11.3-35.el7.x86_64.rpm
wget http://mirrors.ustc.edu.cn/centos/7/os/x86_64/Packages/rpm-python-4.11.3-35.el7.x86_64.rpm

wget http://mirrors.ustc.edu.cn/centos/7/os/x86_64/Packages/python-2.7.5-76.el7.x86_64.rpm
wget http://mirrors.ustc.edu.cn/centos/7/os/x86_64/Packages/python-devel-2.7.5-76.el7.x86_64.rpm
wget http://mirrors.ustc.edu.cn/centos/7/os/x86_64/Packages/python-libs-2.7.5-76.el7.x86_64.rpm
wget http://mirrors.ustc.edu.cn/centos/7/os/x86_64/Packages/python-pycurl-7.19.0-19.el7.x86_64.rpm
wget http://mirrors.ustc.edu.cn/centos/7/os/x86_64/Packages/python-setuptools-0.9.8-7.el7.noarch.rpm
wget http://mirrors.ustc.edu.cn/centos/7/os/x86_64/Packages/python-urlgrabber-3.10-9.el7.noarch.rpm
wget http://mirrors.ustc.edu.cn/centos/7/os/x86_64/Packages/python-iniparse-0.4-9.el7.noarch.rpm
wget http://mirrors.ustc.edu.cn/centos/7/os/x86_64/Packages/python-backports-1.0-8.el7.x86_64.rpm
wget http://mirrors.ustc.edu.cn/centos/7/os/x86_64/Packages/python-backports-ssl_match_hostname-3.5.0.1-1.el7.noarch.rpm
wget http://mirrors.ustc.edu.cn/centos/7/os/x86_64/Packages/python-chardet-2.2.1-1.el7_1.noarch.rpm
wget http://mirrors.ustc.edu.cn/centos/7/os/x86_64/Packages/python-ipaddress-1.0.16-2.el7.noarch.rpm
wget http://mirrors.ustc.edu.cn/centos/7/os/x86_64/Packages/python-kitchen-1.1.1-5.el7.noarch.rpm
wget http://mirrors.ustc.edu.cn/centos/7/os/x86_64/Packages/python-virtualenv-15.1.0-2.el7.noarch.rpm

wget http://mirrors.ustc.edu.cn/centos/7/os/x86_64/Packages/yum-3.4.3-161.el7.centos.noarch.rpm
wget http://mirrors.ustc.edu.cn/centos/7/os/x86_64/Packages/yum-metadata-parser-1.1.4-10.el7.x86_64.rpm
wget http://mirrors.ustc.edu.cn/centos/7/os/x86_64/Packages/yum-utils-1.1.31-50.el7.noarch.rpm
wget http://mirrors.ustc.edu.cn/centos/7/os/x86_64/Packages/yum-plugin-fastestmirror-1.1.31-50.el7.noarch.rpm
wget http://mirrors.ustc.edu.cn/centos/7/os/x86_64/Packages/yum-plugin-protectbase-1.1.31-50.el7.noarch.rpm
wget http://mirrors.ustc.edu.cn/centos/7/os/x86_64/Packages/yum-plugin-aliases-1.1.31-50.el7.noarch.rpm

ps:如想要下载好的rpm请联系QQ：1192612480（无偿）或者访问下面链接（需要五积分--系统默认）.

     https://download.csdn.net/download/fanfan_618/11171598

4、下载完成后安装这些包(--force强制安装)

rpm -Uvh --force --nodeps --replacepkgs *.rpm

5.安装完这些rpm包后，yum就可以正常使用了。yum -v 验证。

ps：

如果安装报错libcrypto.so.10(OPENSSL_1.0.2)(64bit)），则需要先安装openssl-1.0.2k-16.el7.x86_64.rpm、openssl-libs-1.0.2k-16.el7.x86_64.rpm这两个rpm。