PIP is typically installed from the EPEL repository, thus you will first want to ensure EPEL is installed.
The yum list installed command can be used to determine if PIP is installed.
yum list installed | grep -i pip
If PIP is already installed, something like this should be returned.
python2-pip.noarch 8.1.2-12.el7 @epel
If PIP is not installed, the yum install command can be used to install PIP.
yum install python-pip