some errors on my terminal

[greed13]

Hello,
i installed python 3.6 on my ubuntu via this guide

everything seems to wor, but i'm still learning python so i didn't use everything yet, but i get some errors on my terminal from the first command i type, here are the errors :

Traceback (most recent call last):
File "/usr/lib/python3/dist-packages/apport_python_hook.py", line 63, inapport_excepthook
from apport.fileutils import likely_packaged, get_recent_crashes
File "/usr/lib/python3/dist-packages/apport/__init__.py", line 5, in <module>
from apport.report import Report
File "/usr/lib/python3/dist-packages/apport/report.py", line 30, in <module>
import apport.fileutils
File "/usr/lib/python3/dist-packages/apport/fileutils.py", line 23, in <module>
from apport.packaging_impl import impl as packaging
File "/usr/lib/python3/dist-packages/apport/packaging_impl.py", line 23,in <module>
import apt
File "/usr/lib/python3/dist-packages/apt/__init__.py", line 23, in <module>
import apt_pkg
ModuleNotFoundError: No module named 'apt_pkg'

can someone explain me how can i fix this ?

Thank you.