安装python3模块时，yum命令无法执行

/usr/bin/yum: line 2: import: command not found
/usr/bin/yum: line 3: try:: command not found
/usr/bin/yum: line 4: import: command not found
/usr/bin/yum: line 5: except: command not found
/usr/bin/yum: line 23: syntax error near unexpected token `('
/usr/bin/yum: line 23: `""" % (sys.exc_value, sys.version)'

原因：升级python3导致

解决方法：

1.查看yum版本：

rpm -qa |grep yum

2.查看Python版本

cd /usr/bin 目录下

ll python*

https://www.cnblogs.com/1111zhiping-tian/p/10759524.html

查看当前使用的python路径

/root/.pyenv/shims/python

造成yum出错的根本原因就是你动了python2的版本了，yum是要依赖python的，只要你动了（重装、删除等等）都会造成这个错误。网上有很多简单的解决办法都没用;

比如最多的是vim /usr/bin /yum 将第一行改成你 /usr/bin/pythonxxx
这种情况只适用于你新装的python与yum原本依赖的python版本并存的情况下才有效
比如yum原本依赖python2.6 你装了python2.7 这时修改这第一行成/usr/bin/python2.6是可以的
如果原本依赖的python版本没了，那就只能重新安装yum了；

#替换以前的python默认版本（创建新的软连接）

cd /usr/bin/

rm -rf python

ln -s /usr/local/python27/bin/python2.7 ./python

ls -l # 查询 /usr/bin/ 软连接

以上方法依然没有成功

最终方案：

wget  http://mirrors.163.com/centos/7/os/x86_64/Packages/python-2.7.5-89.el7.x86_64.rpm
wget  http://mirrors.163.com/centos/7/os/x86_64/Packages/python-chardet-2.2.1-3.el7.noarch.rpm
wget  http://mirrors.163.com/centos/7/os/x86_64/Packages/python-devel-2.7.5-89.el7.x86_64.rpm
wget  http://mirrors.163.com/centos/7/os/x86_64/Packages/python-iniparse-0.4-9.el7.noarch.rpm
wget  http://mirrors.163.com/centos/7/os/x86_64/Packages/python-kitchen-1.1.1-5.el7.noarch.rpm
wget  http://mirrors.163.com/centos/7/os/x86_64/Packages/python-libs-2.7.5-89.el7.x86_64.rpm
wget  http://mirrors.163.com/centos/7/os/x86_64/Packages/python-pycurl-7.19.0-19.el7.x86_64.rpm
wget  http://mirrors.163.com/centos/7/os/x86_64/Packages/python-setuptools-0.9.8-7.el7.noarch.rpm
wget  http://mirrors.163.com/centos/7/os/x86_64/Packages/python-urlgrabber-3.10-10.el7.noarch.rpm
wget  http://mirrors.163.com/centos/7/os/x86_64/Packages/rpm-python-4.11.3-45.el7.x86_64.rpm
wget  http://mirrors.163.com/centos/7/os/x86_64/Packages/yum-3.4.3-168.el7.centos.noarch.rpm
wget  http://mirrors.163.com/centos/7/os/x86_64/Packages/yum-metadata-parser-1.1.4-10.el7.x86_64.rpm
wget  http://mirrors.163.com/centos/7/os/x86_64/Packages/yum-plugin-aliases-1.1.31-54.el7_8.noarch.rpm
wget  http://mirrors.163.com/centos/7/os/x86_64/Packages/yum-plugin-fastestmirror-1.1.31-54.el7_8.noarch.rpm

wget  http://mirrors.163.com/centos/7/os/x86_64/Packages/yum-plugin-protectbase-1.1.31-54.el7_8.noarch.rpm
wget  http://mirrors.163.com/centos/7/os/x86_64/Packages/yum-updateonboot-1.1.31-54.el7_8.noarch.rpm
wget  http://mirrors.163.com/centos/7/os/x86_64/Packages/yum-utils-1.1.31-54.el7_8.noarch.rpm

下载后安装：