如何在Mac里同时安装python2 和python3

#which python

/Library/anaconda/bin/python

#which python3

/Library/Frameworks/Python.framework/Versions/3.5/bin/python3

# which pip3 or #which pip

/Library/Frameworks/Python.framework/Versions/3.5/bin/pip3

现在系统默认的pip是python3的怎么找python2 的pip呢？在python2存放的目录下边找。

#/Library/anaconda/bin/pip

#/Library/anaconda/bin/pip --version

pip 7.1.2 from /Library/anaconda/lib/python2.7/site-packages (python 2.7)

Ctrl + D 退出Python环境exist(  )

那么如何用pip install python 的 packages呢？