Linux 系统为 CentOS Linux release 7.4.1708

手贱、手贱、手贱 删了python 导致yum不可用。百度一大圈，重装yum和python后，老是报各种各样的错。历经磨难，终于自己总结了一套，亲测可用，分享一下。

1. 首先卸载现有python

    rpm -qa|grep python|xargs rpm -ev --allmatches --nodeps #卸载python
    whereis python |xargs rm -frv ##删除所有残余文件
    whereis python ##验证删除，返回无结果

1. 删除现有的yum

    rpm -qa|grep yum|xargs rpm -ev --allmatches --nodeps #删除yum
    whereis yum |xargs rm -frv #删除残留文件
    whereis yum #验证删除完成

1. 找到下载文件源
   首先在这里找到服务器对应的版本，如 7.4.1708 进入这里目录 找到对应版本的rpm，替换下面的文件。

1. 下载并安装，注意顺序，先安装python 然后 yum。不然安装后还会报错，重新来一遍。

   # python安装
   1.  rpm -ivh --nodeps http://vault.centos.org/7.4.1708/os/x86_64/Packages/python-2.7.5-58.el7.x86_64.rpm
   2.  rpm -ivh --nodeps http://vault.centos.org/7.4.1708/os/x86_64/Packages/python-devel-2.7.5-58.el7.x86_64.rpm
   3.  rpm -ivh --nodeps http://vault.centos.org/7.4.1708/os/x86_64/Packages/python-iniparse-0.4-9.el7.noarch.rpm
   4.  rpm -ivh --nodeps http://vault.centos.org/7.4.1708/os/x86_64/Packages/python-libs-2.7.5-58.el7.x86_64.rpm
   5.  rpm -ivh --nodeps http://vault.centos.org/7.4.1708/os/x86_64/Packages/python-pycurl-7.19.0-19.el7.x86_64.rpm
   6.  rpm -ivh --nodeps http://vault.centos.org/7.4.1708/os/x86_64/Packages/python-urlgrabber-3.10-8.el7.noarch.rpm
   7.  rpm -ivh --nodeps http://vault.centos.org/7.4.1708/os/x86_64/Packages/rpm-python-4.11.3-25.el7.x86_64.rpm

   # yum安装
   8.  rpm -ivh --nodeps http://vault.centos.org/7.4.1708/os/x86_64/Packages/yum-3.4.3-154.el7.centos.noarch.rpm
   9.  rpm -ivh --nodeps http://vault.centos.org/7.4.1708/os/x86_64/Packages/yum-metadata-parser-1.1.4-10.el7.x86_64.rpm
   10. rpm -ivh --nodeps http://vault.centos.org/7.4.1708/os/x86_64/Packages/yum-plugin-fastestmirror-1.1.31-42.el7.noarch.rpm

1. 验证

   # 验证python
   python
   # 验证yum
   yum