The DOT graph description language
defines a file format that is most often used in the context of graph
visualization with Graphviz.
NetworkX provides an interface to Graphviz via pygraphviz,
pygraphviz is installed,
nx_agraph can be used to
read and write files in DOT format.
Returns a NetworkX graph from a dot file on path.
Write NetworkX graph G to Graphviz dot format on path.