If you have pip installed in both pythons, and both are in your path, just use:
$ pip-2.7 install PACKAGENAME
$ pip-3.2 install PACKAGENAME
References:
- http://www.pip-installer.org/docs/pip/en/0.8.3/news.html#id4
- https://github.com/pypa/pip/issues/200
This is a duplicate of question #2812520