ModuleNotFoundError: No module named 'matplotlib._path'
I finally started using anaconda and installing everything in one environment. In this way, I save and import everything that I want in this environment without any confusion.
While I installed properly the matplotlib and seaborn. I was able to import matplotlib but when I was trying to import the seaborn I got the following error message. ModuleNotFoundError: No module named 'matplotlib._path' . Same if I was trying to import matplotlib.pyplot.
After spending a lot of time googling and trying this and that, installing and unistaling, finally, I
first checked out the 
import sys
sys.path to see what are the folders that it searches for the installed packages.
my result was something like this.
['',
 'C:\\Users\\gsotiropoulos\\AppData\\Local\\conda\\conda\\envs\\py36\\python36.zip',
 'C:\\Users\\gsotiropoulos\\AppData\\Local\\conda\\conda\\envs\\py36\\DLLs',
 'C:\\Users\\gsotiropoulos\\AppData\\Local\\conda\\conda\\envs\\py36\\lib',
 'C:\\Users\\gsotiropoulos\\AppData\\Local\\conda\\conda\\envs\\py36',
 'C:\\Users\\gsotiropoulos\\AppData\\Roaming\\Python\\Python36\\site-packages',
 'C:\\Users\\gsotiropoulos\\AppData\\Local\\conda\\conda\\envs\\py36\\lib\\site-packages',
 'C:\\Users\\gsotiropoulos\\AppData\\Local\\conda\\conda\\envs\\py36\\lib\\site-packages\\win32',
 'C:\\Users\\gsotiropoulos\\AppData\\Local\\conda\\conda\\envs\\py36\\lib\\site-packages\\win32\\lib',
 'C:\\Users\\gsotiropoulos\\AppData\\Local\\conda\\conda\\envs\\py36\\lib\\site-packages\\Pythonwin',
 'C:\\Users\\gsotiropoulos\\AppData\\Local\\conda\\conda\\envs\\py36\\lib\\site-packages\\IPython\\extensions',
 'C:\\Users\\gsotiropoulos\\.ipython']
then as suggested I import matplotlib as mpl and mpl.__path__ seeing that I import matplotlib from the folder 'C:\\Users\\gsotiropoulos\\AppData\\Roaming\\Python\\Python36\\site-packages' Which is not the one from anaconda and it is older. I am not sure if it would be better to just remove this folder completely.
However, as I understand, python first searched there and found a matplotlib package which was outdated. I simply changed the name of the `matplotlib' to something like 'matplotlib_test' and then the library is installed from one of the anaconda folders and the problem is solved.
As I understand I installed in the past python but the 'roaming' folder did not get unistalled. Is that right?
I wonder if I should delete the "roaming" folder to avoid similar other problems.