cannot import name '_tkagg' from 'matplotlib.backends' in python 2.7 and python 3.8

[lpagani91]

I have problems importing tkagg in a python program, though it used to work (I ran the same python program in the past):

In [9]: matplotlib.__version__                                                  
Out[9]: '3.1.3'
In [10]: from matplotlib.backends.backend_tkagg import FigureCanvasTkagg        
---------------------------------------------------------------------------
ImportError                               Traceback (most recent call last)
<ipython-input-10-b2c6c8b92aa8> in <module>
----> 1 from matplotlib.backends.backend_tkagg import FigureCanvasTkagg

/opt/local/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/matplotlib/backends/backend_tkagg.py in <module>
----> 1 from . import _backend_tk
      2 from .backend_agg import FigureCanvasAgg
      3 from ._backend_tk import (
      4     _BackendTk, FigureCanvasTk, FigureManagerTk, NavigationToolbar2Tk)
      5 

/opt/local/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/matplotlib/backends/_backend_tk.py in <module>
     20 from matplotlib.figure import Figure
     21 from matplotlib.widgets import SubplotTool
---> 22 from . import _tkagg
     23 
     24 try:

ImportError: cannot import name '_tkagg' from 'matplotlib.backends' (/opt/local/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/matplotlib/backends/__init__.py)

I searched the web but all similar problems were linked to Windows or Ubuntu. Tkinter was not installed in my latest Python versions so I added it and some people mention that I should uninstall matplotlib and reinstall it after having installed Tkinter but it did not help.

[mf2k (Frank Schima)]

In the future, please use WikiFormatting and add the port maintainer(s) to Cc (port info --maintainers py38-matplotlib), if any.