"ModuleNotFoundError: No module named 'apt_pkg'" trying to install Moka

Question

I wanna install moka theme on my ubuntu with following command:

sudo add-apt-repository ppa:moka/stable

But get error:

Original exception was:
Traceback (most recent call last):
  File "/usr/bin/add-apt-repository", line 11, in <module>
    from softwareproperties.SoftwareProperties import SoftwareProperties, shortcut_handler
  File "/usr/lib/python3/dist-packages/softwareproperties/SoftwareProperties.py", line 27, in <module>
    import apt_pkg
ModuleNotFoundError: No module named 'apt_pkg'

python -V: 2.7.6

python3 -V: 3.6.3

What should I do?

Solution

See zhazha's answer on python-dev installation error: ImportError: No module named apt_pkg - Stack Overflow for a solution. In short:

cd /usr/lib/python3/dist-packages
sudo ln -s apt_pkg.cpython-36m-x86_64-linux-gnu.so apt_pkg.so