square brackets in pip install
"The square bracket contains the 'extra' option's information defined in setup.py that pip will use to install
additional dependencies.
pip install "splinter[django]"
To be specific, the above line will install first the 'splinter' package, then install the extra dependencies
the 'splinter' project requires with the 'django' option specified in a setup.py of 'splinter' project."
https://stackoverflow.com/questions/46775346/what-do-square-brackets-mean-in-pip-install
