pypa/pip — pull request #1506 by SamuelMarks (2014-01-26 09:03:14+00:00)
Title: Added a simple `--upgrade_all` argument

Trivial—naïve?—implementation of an `--upgrade_all` argument [+ some very minor refactoring (DRY)]

Issue reference: https://github.com/pypa/pip/issues/59
SO reference: http://stackoverflow.com/questions/2720014/upgrading-all-packages-with-pip