I had the same issue on Ubuntu(14.04) with Jupyter.
To solve it I've added the dot library to python sys.path
First: check if dot is installed,
Then:
find his path whereis dot
-> /local/notebook/miniconda2/envs/ik2/bin/dot
Finally in python script : sys.path.append("/local/notebook/miniconda2/envs/ik2/bin/dot")