https://www.pycon.kr/2017/program/151

17. $ pip --version
pip 9.0.1 from /Users/tkim/.pyenv/versions/2.7.13/lib/python2.7/site-packages
(python 2.7)
$ python2.7 -m pip --version
pip 9.0.1 from /Users/tkim/.pyenv/versions/2.7.13/lib/python2.7/site-packages
(python 2.7)
$ pip3.5 --version # 이미 alias가 만들어져 있을 수 있음
pip 9.0.1 from /Users/tkim/.pyenv/versions/3.5.2/lib/python3.5/site-packages
(python 3.5)
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