matplotlib.pyplot giving error 'ImportError: No module named Tkinter' on python 2.7
I found this answer to a similar question however, which I believe would solve your issue.https://stackoverflow.com/a/49988926/8775307It imports matplotlib.pyplot without tkinter. I don't know if all the features are actually included though, so you'll have to test and let us know :).
You could always write to the administrator and request Tkinter - it's a widely used and useful package, so they might be willing to include it.