ImportError: No module named tkinter. Mac OS Terminal
Make sure your default python , the one that the terminal calls has tkinter installed.
So run 'python --version' in the terminal and if that yields 3.7 then your default python is 3.7.
Now try to import tkinter using that same python version.
open the terminal and run python then run import tkinter as tk
If that does not yield an error saying that the module was not found then most probably you are running the executable with the wrong permissions.