Не могу найти или установить tkinter

У меня проблема с модулем tkinter в Ubuntu 16.04. Он должен быть загружен для запуска программы на python3.6, но не может быть найден:

File "/usr/local/bin/declooptor", line 11, in <module>
     load_entry_point('declooptor==0.1.0', 'console_scripts', 'declooptor')() File
 "/usr/local/lib/python3.6/dist-packages/pkg_resources/__init__.py",
 line 487, in load_entry_point
     return get_distribution(dist).load_entry_point(group, name)   File "/usr/local/lib/python3.6/dist-packages/pkg_resources/__init__.py",
 line 2728, in load_entry_point
     return ep.load()   File "/usr/local/lib/python3.6/dist-packages/pkg_resources/__init__.py",
 line 2346, in load
     return self.resolve()   File "/usr/local/lib/python3.6/dist-packages/pkg_resources/__init__.py",
 line 2352, in resolve
     module = __import__(self.module_name, fromlist=['__name__'], level=0)   File
 "/usr/local/lib/python3.6/dist-packages/declooptor-0.1.0-py3.6.egg/declooptor/detector.py",
 line 39, in <module>   File
 "/usr/local/lib/python3.6/dist-packages/matplotlib/pyplot.py", line
 2374, in <module>
     switch_backend(rcParams["backend"])   File "/usr/local/lib/python3.6/dist-packages/matplotlib/pyplot.py", line 207, in switch_backend
     backend_mod = importlib.import_module(backend_name)   File "/usr/lib/python3.6/importlib/__init__.py", line 126, in import_module
     return _bootstrap._gcd_import(name[level:], package, level)   File "/usr/local/lib/python3.6/dist-packages/matplotlib/backends/backend_tkagg.py",
 line 1, in <module>
     from . import _backend_tk   File "/usr/local/lib/python3.6/dist-packages/matplotlib/backends/_backend_tk.py", line 5, in <module>
    import tkinter as Tk ModuleNotFoundError: No module named 'tkinter'

Но когда я печатаю sudo apt install python3-tk Я получил:

Reading package lists... Done
Building dependency tree       
Reading state information... Done
python3-tk is already the newest version (3.5.1-1).
0 upgraded, 0 newly installed, 0 to remove and 1 not upgraded.

which python3.6 возвращается /usr/bin/python3.6

Я проверил папки /usr/lib/python3/dist-packages/, /usr/lib/python3.5 а также /usr/lib/python3.6 но нет tkinter папку, хотя они могут иметь другое имя сейчас?

Кто-нибудь знает, что делать?