The issue is probably because of the the default GCC version on Ubuntu 16.04 which is GCC 5.3.1. As of MATLAB R2018a, MATLAB external interfaces required to use GCC 6.3.x on Linux distributions. If the G++ libraries are upgraded to the required version, the dependencies will be resolved and the library can be imported into Python as normal.
Please execute the below commands on the Linux Terminal for upgrading the gcc version on Debian distributions like Ubuntu:
$ LD_LIBRARY_PATH=/usr/local/lib64/:$LD_LIBRARY_PATH
$ export LD_LIBRARY_PATH
$ sudo apt-add-repository ppa:ubuntu-toolchain-r/test
$ sudo apt-get update
$ sudo apt-get install gcc-6 g++-6
Please note that upgrading gcc might effect other applications running on the computer.
Please see the following documentation page for further reference: https://www.mathworks.com/support/compilers.html
