如何在virtualenv中使用python 2和3

Question

I have a virtualenv (python2api) made in python2.7 on Ubuntu 16.04. In the virtualenv I installed python3.5:

$ virtualenv -p python3.5 python2api

Then I installed pip3:

$ sudo apt-get install python3-pip

But when I run 'which pip' it shows that pip3 installed outside of the virtualenv and any pip3 packages I install go to '/usr/lib/python2.7' instead of '/var/env/python2api/lib/python3.5/site-packages/'.

(python2api) user@comp:/var/env/python2api/lib$ which pip
/var/env/python2api/bin/pip
(python2api) user@comp:/var/env/python2api/lib$ which pip3
/usr/bin/pip3

Is there a way to make pip3 install packages in the virtualenv? It seems like only python2 or only python3 packages can exist in the virtualenv.

Answer 1

A virtualenv encapsulates one version of Python .

You can't use it to manage more than one version, and Python 2.x and Python 3.x are separate versions here.

Use two separate virtualenvs, one for each Python version.