Python - Using virtualenv - python3

Step 1: Create a virtual environment for python3:

/opt3$ virtualenv -p python3 python3runs01
Already using interpreter /usr/bin/python3
Using base prefix '/usr'
New python executable in /opt3/python3runs01/bin/python3
Also creating executable in /opt3/python3runs01/bin/python
Installing setuptools, pkg_resources, pip, wheel...done.
/opt3$ 

Step 2: Change directory to the virtual environment folder:

/opt3$ cd python3runs01

Step 3: Activate the virtual environment:

/opt3/python3runs01$ source bin/activate

(python3runs01) /opt3/python3runs01$ 

Notice that, after you activate, a prompt is added. 

(python3runs01) /opt3/python3runs01$ ls -l

total 0

drwxr-xr-x 2 ubuntu ubuntu 320 Jan 29 11:50 bin

drwxr-xr-x 2 ubuntu ubuntu  60 Jan 29 11:50 include

drwxr-xr-x 3 ubuntu ubuntu  60 Jan 29 11:50 lib

drwxr-xr-x 3 ubuntu ubuntu  60 Jan 29 11:50 share

(python3runs01) /opt3/python3runs01$

Step 4: Deactivate from virtual environment:

(python3runs01) /opt3/python3runs01$ deactivate

/opt3/python3runs01$

References:

• https://stackoverflow.com/questions/23842713/using-python-3-in-virtualenv
• https://stackoverflow.com/questions/990754/how-to-leave-exit-deactivate-a-python-virtualenv