Script that should upgrade old pip-versions shipped with Ubuntu to the latest version available from PyPI

upgrade-pip.sh

#! /bin/bash

upgrade_pip2 () {
    # Installs latest version of pip for Python2, if any version is already installed
    if pip2 &> /dev/null
        then 
            echo "*** Uninstalling old version of pip for Python2..."
            sudo apt-get remove python-pip -qq
            echo "*** Installing/upgrading setuptools for Python2..."
            sudo apt-get install python-setuptools -qq
            echo "*** Using easy_install to get newest version of pip for Python2..."
            sudo easy_install -U pip
    fi 
}

upgrade_pip3 () {
            echo "*** Uninstalling old version of pip for Python3..."
            sudo apt-get remove python3-pip -qq
            echo "*** Installing/upgrading setuptools for Python3..."
            sudo apt-get install python3-setuptools -qq
            echo "*** Using easy_install to get newest version of pip for Python3..."
            sudo easy_install3 -U pip
}

# find out if pip for Python2 is the default version if plain "pip" is run without version number
if pip -V | grep -q "(python 2"
    then 
        # install pip for Python2 last, so that it will become the default
        upgrade_pip3
        upgrade_pip2 
    else
        # install pip for Python3 last, so that it will become the default
        upgrade_pip2
        upgrade_pip3
fi