What is the purpose "pip install --user ..."?
pip install --help:
--user Install to the Python user install directory for your platform. Typically ~/.local/, or %APPDATA%\Python on Windows. (See the Python documentation for site.USER_BASE for full details.)
The documentation for site.USER_BASE is a terrifying wormhole of interesting *NIX subject matter that I don't understand.
What is the purpose of
--user in plain english? Why would intalling the package to
~/.local/ matter? Why not just put an executable somewhere in my $PATH?
pip defaults to installing Python packages to a system directory (such as
/usr/local/lib/python3.4). This requires root access.
--user makes pip install packages in your home directory instead, which doesn't require any special privileges.