How does one install virtualenvwrapper for both Python 2.7 and 3.6 versions? My default Python environment is Python 3.6 and as such virtualenvwrapper is installed for Python 3.6 and not 2.7. I'm using macOS Sierra 10.12.6.
You need only install virtualenvwrapper once. See the warning about installing on your base Python installation.
Using Homebrew package manager install python2 and python3.
Making a virtual environment is a matter of passing a flag.
# make py3
mkvirtualenv py3 --python=python3
# make py2
mkvirtualenv py2 --python=python2
来源：https://stackoverflow.com/questions/45917859/install-virtualenvwrapper-for-python-2-7-and-3-6-simultaneously