Install Python's pip under centos7

When the root user uses yum install -y python-pip, the following error will be reported:

No package python-pip available

Error:Nothing to do

The workaround is as follows:

　　First install the epel extension source:

　　yum -y install epel-release

　　Once the update is complete, you can install pip:

　　yum -y install python-pip

　　Clear the cache after the installation is complete:

　　yum clean all

This is the command used when the root user is used. If the current user does not have root privileges, add sudo.

This method can also be used in other Linux-like centos-derived distributions.