Python quit working and now I get "Illegal instruction: 4" message
I found a solution but I'm not 100% sure its the whole answer. My test codes now run fine. I very carefully reloaded the Anaconda distribution for python 3.7 and i made sure to activate my virtual environment ASAP.  When Anaconda is loaded, it also loads many packages. I noticed that it did not load numpy, although it had in the past. It did load something called numbpy, I think it was. Anyway, making sure my virtual environment was activated I loaded numpy for my environment by typing:

conda install -n yourenvname [package]


I also did the same for vpython. Now everything seems to work. I suppose the problem was trying to import a package that hadn't been installed  properly. I'm sure I've committed the foul-up before but I don't recall ever seeing "Illegal instruction 4".