更新yum源导致yum不可用

当安装和yum配置相关的包后报yum模块找不到

yum install -y yum-utils device-mapper-persistent-data lvm2
 yum list|grep yum
There was a problem importing one of the Python modules
required to run yum. The error leading to this problem was:

   No module named yum
# 查看/usr/bin/yum
more /usr/bin/yum
#!/usr/bin/python
import sys
try:
    import yum
except ImportError:
    print >> sys.stderr, """

yum 包是集成在Python2.6版本中的，而Linux默认都是安装Python2.6,且执行文件为/usr/bin/python2.6

上述包安装后，/usr/bin/yum文件被变更，Python执行路径变为了/usr/bin/python，将其改为/usr/bin/python2.6即可