自己误将yum卸载， 在重装时由于依赖问题一直报错： error: Failed dependencies:     /usr/bin/python is needed by yum-3.4.3-163.el7.centos.noarch     python >= 2.4 is needed by yum-3.4.3-163.el7.centos.noarch     python(abi) = 2.7 is needed by yum-3.4.3-163.el7.centos.noarch     python-iniparse is needed by yum-3.4.3-163.el7.centos.noarch     python-sqlite is needed by yum-3.4.3-163.el7.centos.noarch     python-urlgrabber >= 3.10-8 is needed by yum-3.4.3-163.el7.centos.noarch     rpm-python is needed by yum-3.4.3-163.el7.centos.noarch     libpython2.7.so.1.0()(64bit) is needed by yum-metadata-parser-1.1.4-10.el7.x86_64     python(abi) = 2.7 is needed by yum-metadata-parser-1.1.4-10.el7.x86_64     1、查看yum安装包 # rpm -qa | grep yum yum-plugin-fastestmirror-1.1.31-52.el7.noarch yum-metadata-parser-1.1.4-10.el7.x86_64 yum-utils-1.1.31-52.el7.noarch      2、将其全部卸载 #rpm -e yum-plugin-fastestmirror-1.1.31-52.el7.noarch --nodeps #rpm -e yum-metadata-parser-1.1.4-10.el7.x86_64 --nodeps #rpm -e yum-utils-1.1.31-52.el7.noarch --nodeps   3、在http://mirrors.163.com/centos/7/os/x86_64/Packages/下载如下20个包   libxml2-python-2.9.1-6.el7_2.3.x86_64.rpm                     python-ipaddress-1.0.16-2.el7.noarch.rpm   lvm2-python-libs-2.02.185-2.el7.x86_64.rpm python-kitchen-1.1.1-5.el7.noarch.rpm      yum-3.4.3-163.el7.centos.noarch.rpm python-2.7.5-86.el7.x86_64.rpm                                 python-libs-2.7.5-86.el7.x86_64.rpm        yum-metadata-parser-1.1.4-10.el7.x86_64.rpm python-backports-ssl_match_hostname-3.5.0.1-1.el7.noarch.rpm   python-pycurl-7.19.0-19.el7.x86_64.rpm     yum-plugin-aliases-1.1.31-52.el7.noarch.rpm python-chardet-2.2.1-3.el7.noarch.rpm                          python-setuptools-0.9.8-7.el7.noarch.rpm   yum-plugin-fastestmirror-1.1.31-52.el7.noarch.rpm python-devel-2.7.5-86.el7.x86_64.rpm                           python-urlgrabber-3.10-9.el7.noarch.rpm    yum-plugin-protectbase-1.1.31-52.el7.noarch.rpm python-iniparse-0.4-9.el7.noarch.rpm                           rpm-python-4.11.3-40.el7.x86_64.rpm        yum-utils-1.1.31-52.el7.noarch.rpm     4、下载完成后执行 #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     5、成功安装   6、如果将python换成python3的话，运行yum会报错 [root@iz2ze3ogy01eqvjs99e8nez python]# yum   File "/usr/bin/yum", line 30     except KeyboardInterrupt, e:                             ^ SyntaxError: invalid syntax   修改 vi /etc/usr/yum 第一行为 #!/usr/bin/python2