Trying asking for user to choose file

Not sure if tkinter is a default module in all python installations. In
any case, I’m starting to play with this.
Some testing of getting OS type

We may need to get OS type so that we can properly substring file
paths. This is because I plan to have the user give us the location of
one file(?) or type in the folder path(?), and then iterate through all
of the files there. In either case, the path to the folder is needed