##下載yum源(Centos 7 為例)
[root@localhost ~]# wget http://mirror.centos.org/centos/7/extras/x86_64/Packages/epel-release-7-11.noarch.rpm
##安裝yum源
[root@localhost ~]# yum install -y epel-release-7-11.noarch.rpm
##安裝sl命令(小火車)
[root@localhost ~]# yum install -y sl
##安裝ipython命令
[root@localhost ~]# yum install -y ipython