1.刪除已有的Python
#rpm -qa|grep python|xargs rpm -ev --allmatches --nodeps
#whereis python |xargs rm -frv
#whereis python
2.刪除已有的yum
#rpm -qa|grep yum|xargs rpm -ev --allmatches --nodeps
#whereis yum |xargs rm -frv
3. 創建兩個目錄用於存放Python和yum的rpm包
#mkdir /usr/local/src/python
#mkdir /usr/local/src/yum
4. 查到centOS的版本並下載相應的rpm包
#cat /etc/redhat-release
對應的rpm包下載網址：http://mirrors.ustc.edu.cn/centos/7.7.1908/os/x86_64/Packages/
http://mirrors.ustc.edu.cn/centos/7.7.1908/os/x86_64/Packages/python-2.7.5-86.el7.x86_64.rpm
http://mirrors.ustc.edu.cn/centos/7.7.1908/os/x86_64/Packages/python-devel-2.7.5-86.el7.x86_64.rpm
http://mirrors.ustc.edu.cn/centos/7.7.1908/os/x86_64/Packages/python-iniparse-0.4-9.el7.noarch.rpm
http://mirrors.ustc.edu.cn/centos/7.7.1908/os/x86_64/Packages/python-pycurl-7.19.0-19.el7.x86_64.rpm
http://mirrors.ustc.edu.cn/centos/7.7.1908/os/x86_64/Packages/python-setuptools-0.9.8-7.el7.noarch.rpm
http://mirrors.ustc.edu.cn/centos/7.7.1908/os/x86_64/Packages/python-libs-2.7.5-86.el7.x86_64.rpm
http://mirrors.ustc.edu.cn/centos/7.7.1908/os/x86_64/Packages/python-urlgrabber-3.10-9.el7.noarch.rpm
http://mirrors.ustc.edu.cn/centos/7.7.1908/os/x86_64/Packages/rpm-python-4.11.3-40.el7.x86_64.rpm
進入到python目錄下
#cd /usr/local/src/python
將上面的rpm包下載到python目錄
cd /usr/local/src/yum
http://mirrors.ustc.edu.cn/centos/7.7.1908/os/x86_64/Packages/yum-3.4.3-163.el7.centos.noarch.rpm
http://mirrors.ustc.edu.cn/centos/7.7.1908/os/x86_64/Packages/yum-metadata-parser-1.1.4-10.el7.x86_64.rpm
http://mirrors.ustc.edu.cn/centos/7.7.1908/os/x86_64/Packages/yum-utils-1.1.31-52.el7.noarch.rpm
http://mirrors.ustc.edu.cn/centos/7.7.1908/os/x86_64/Packages/yum-plugin-fastestmirror-1.1.31-52.el7.noarch.rpm
http://mirrors.ustc.edu.cn/centos/7.7.1908/os/x86_64/Packages/yum-plugin-protectbase-1.1.31-52.el7.noarch.rpm
http://mirrors.ustc.edu.cn/centos/7.7.1908/os/x86_64/Packages/yum-plugin-aliases-1.1.31-52.el7.noarch.rpm
5.安裝python
#rpm -ivh python-* rpm-python-*
出現上面依賴包的解決方法：
#rpm -ivh python-* rpm-python-* --nodeps --force
輸入#python 查看Python是否按照成功
6. 安裝yum
#cd /usr/local/src/yum
#rpm -ivh yum-* --nodeps --force
