Installing pygments to be able to use lexer & highlighter for Mathematica

Question

I'd like to try the lexer and highlighter for Mathematica that's based on Pygments, but I'm lost in a morass of getting Pygments installed.

Here's what I have so far.

• I'm using MacPorts python37 (invoked from command line by "python").
• Again with MacPorts I have installed the python 3.7 setuptools (port py37-setuptools, wheel (port py37-wheel), and pip (port py37-pip).

• I created a virtual environment via:

  python -m venv ~/PyithonVirtualEnvironments/pygments
  

• I'm invoking (I hope) that environment by command:

  python -m venv pygments
  

• With Pygments-2.2.0-py2.py3-none-any.whl downloaded, I try

   pip install "Pygments-2.2.0-py2.py3-none-any.whl"
  

but this fails with:

Installing collected packages: Pygments
Could not install packages due to an EnvironmentError: [Errno 13]   
Permission denied: '/opt/local/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/pygments'
Consider using the `--user` option or check the permissions.

Evidently this install is trying to put pygments not into the virtual enviroment location (which I thought was the purpose of the virtual environment) but rather into the MacPorts /opt location (which is definitely where I do not want it to be).

How should I proceed here?

Comment: I do hate it when somebody creates a potentially useful tool (for example, for Mathematica), then leaves everything to the user to work through a seemingly infinite regress to get it to work!