"E: Unable to locate package python-pip" on Ubuntu 18.04

Try the following commands in terminal, this will work better:

apt-get install curl

curl https://bootstrap.pypa.io/pip/2.7/get-pip.py -o get-pip.py

python get-pip.py

Try following command sequence on Ubuntu terminal:

sudo apt-get install software-properties-common
sudo apt-add-repository universe
sudo apt-get update
sudo apt-get install python-pip

ls /bin/python*

Identify the highest version of python listed. If the highest version is something like python2.7 then install python2-pip If its something like python3.8 then install python3-pip

Example for python3.8:

sudo apt-get install python3-pip