While using command 'complete', I am getting an error saying:
Traceback (most recent call last): File "$<$string>", line 1, in $<$module> ImportError: No module named 'sympy'
In order to use any of the component functionality you need to have the sympy Python package installed. On most systems this is done with
sympy
sudo pip3 install sympy
(see the github page for some more system-specific info in case the above does not do the trick).