Richard Jones' Log: devpi quick-start
(devpi is the caching proxy for PyPI which does a bunch of other things too but mostly just speeds up "pip install" and isolates you from network issues - or complete lack of connectivity)
devpi in 60 seconds
Step 1: create a virtualenv
Step 2: install devpi
pip install devpi
Step 3: run devpi
Step 4: use devpi (noting the URL from the previous command output)
devpi use --set-cfg [URL]/root/pypi
Step 5: profit!
pip install yarg
The first installation will call out to the Internet but subsequent installs will use the cached version.