Yum安装，Linux自带Python卸载 安装

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 

下面提供两个centos的版本 一个是7.5.1804的  一个是7.8.2003的

7.5.1804版本的Centos:

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

wget https://vault.centos.org/7.8.2003/os/x86_64/Packages/subscription-manager-1.24.26-1.el7.centos.x86_64.rpm

7.5.2003版本的Centos:

wget http://vault.centos.org/7.8.2003/os/x86_64/Packages/lvm2-python-libs-2.02.186-7.el7.x86_64.rpm
wget http://vault.centos.org/7.8.2003/os/x86_64/Packages/libxml2-python-2.9.1-6.el7.4.x86_64.rpm
wget http://vault.centos.org/7.8.2003/os/x86_64/Packages/python-libs-2.7.5-88.el7.x86_64.rpm
wget http://vault.centos.org/7.8.2003/os/x86_64/Packages/python-ipaddress-1.0.16-2.el7.noarch.rpm
wget http://vault.centos.org/7.8.2003/os/x86_64/Packages/python-backports-1.0-8.el7.x86_64.rpm
wget http://vault.centos.org/7.8.2003/os/x86_64/Packages/python-backports-ssl_match_hostname-3.5.0.1-1.el7.noarch.rpm
wget http://vault.centos.org/7.8.2003/os/x86_64/Packages/python-2.7.5-88.el7.x86_64.rpm
wget http://vault.centos.org/7.8.2003/os/x86_64/Packages/python-iniparse-0.4-9.el7.noarch.rpm
wget http://vault.centos.org/7.8.2003/os/x86_64/Packages/python-pycurl-7.19.0-19.el7.x86_64.rpm
wget http://vault.centos.org/7.8.2003/os/x86_64/Packages/python-urlgrabber-3.10-10.el7.noarch.rpm
wget http://vault.centos.org/7.8.2003/os/x86_64/Packages/python-setuptools-0.9.8-7.el7.noarch.rpm
wget http://vault.centos.org/7.8.2003/os/x86_64/Packages/python-kitchen-1.1.1-5.el7.noarch.rpm
wget http://vault.centos.org/7.8.2003/os/x86_64/Packages/python-chardet-2.2.1-3.el7.noarch.rpm
wget http://vault.centos.org/7.8.2003/os/x86_64/Packages/rpm-python-4.11.3-43.el7.x86_64.rpm
wget http://vault.centos.org/7.8.2003/os/x86_64/Packages/yum-utils-1.1.31-53.el7.noarch.rpm
wget http://vault.centos.org/7.8.2003/os/x86_64/Packages/yum-3.4.3-167.el7.centos.noarch.rpm
wget http://vault.centos.org/7.8.2003/os/x86_64/Packages/yum-metadata-parser-1.1.4-10.el7.x86_64.rpm
wget http://vault.centos.org/7.8.2003/os/x86_64/Packages/yum-plugin-aliases-1.1.31-53.el7.noarch.rpm
wget http://vault.centos.org/7.8.2003/os/x86_64/Packages/yum-plugin-protectbase-1.1.31-53.el7.noarch.rpm
wget http://vault.centos.org/7.8.2003/os/x86_64/Packages/yum-plugin-fastestmirror-1.1.31-53.el7.noarch.rpm



wget https://vault.centos.org/7.8.2003/os/x86_64/Packages/subscription-manager-1.24.26-1.el7.centos.x86_64.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

rpm -ivh subscription-manager-1.24.26-1.el7.centos.x86_64.rpm  (注意  这个填你下载的版本)

安装成功后执行

yum
python

如果提示 有search-disabled-repos.conf   productbase.conf 等文件找不到的  就新建个这个文件，然后内容如下

[main]
enabled=0