Answer by MechanisM for Install a package and write to requirements.txt with pip

Just add smth like

function pips() {    echo $'\n'$1 >> requirements.txt; pip install $1}

into your .bashrc or .bash_profile and use pips command to install package and save it's name into requirements.txtexample:

pips django-waffle

based on Akash Kothawale comment :)