Hello people,
This is my first post on the forum, I will try to make it as correct and complete as possible if you have any tips to improve my post I will gladly accept it.
I’m having trouble running code written in Python that uses Tkinter.
I will try to describe in detail my actions to facilitate the identification of the error.
I started a course at Coursera on DSP (Digital Signal Processing) where it is suggested to install a tool written in python (and a little bit of C).

link on Github:
sms-tools Github link

Using pyenv/virtualenv/virtualenvwrapper I created an environment with Python 3.7.5, as recommended in the “How to use” section of the repository.

I installed the required libraries in my environment by pip:

%pip install ipython numpy matplotlib scipy cython 

I compiled some C functions in the “/sms-tools/software/models/utilFunctions_C” directory with the following command:

%python compileModule.py build_ext --inplace 

Finally, I run the models GUI in the directory “/sms-tools/software/models_interface”

and I get the following message:

 Traceback (most recent call last):
  File "models_GUI.py", line 6, in <module>
    from Tkinter import *   ## notice capitalized T in Tkinter 
ModuleNotFoundError: No module named 'Tkinter'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "models_GUI.py", line 9, in <module>
    from tkinter import *   ## notice lowercase 't' in tkinter here
  File "/home/tuliochiodi/.pyenv/versions/3.7.5/lib/python3.7/tkinter/__init__.py", line 36, in <module>
    import _tkinter # If this fails your Python may not be configured for Tk
ModuleNotFoundError: No module named '_tkinter' 

I will now describe some of my attempts to solve the problem:

Looking at Tkinter section in Python Wiki I tried installing Tcl and Tk.

but it was already installed. after that I tried installing with pip:

and

and the error remains the same.

I also tried to create a symlink with this code:

 %ln -s /usr/lib/python3.8/lib-dynload/_tkinter.cpython-38-x86_64-linux-gnu.so _tkinter.cpython-38-x86_64-linux-gnu.so 

the symlink was created in the following folders:

 ~/.ve/Coursera_DSP/lib/python3.7/lib-dynload 

and

 .pyenv/versions/3.7.5/lib/python3.7/lib-dynload 

But I still get the same error.

I appreciate if anyone has any suggestions and I apologize for the language errors, since English is not my mother tongue.