Errors while executing codes after importing pygraphviz


I was going throug the wonderful article,
I have installed graphviz and pygraphviz . Packages are showing up in pip freeze.
But am getting errors while executing following codes.

import pygraphviz as pgv
d={‘1’: {‘2’: None}, ‘2’: {‘1’: None, ‘3’: None}, ‘3’: {‘1’: None}}
A = pgv.AGraph(data=d)
print(A) # This is the ‘string’ or simple representation of the Graph



Hey - Can you copy the whole traceback here? That would be more informative of the problem