GUESS is an exploratory data analysis and visualization tool for graphs and networks. The system contains a domain-specific embedded language called Gython (an extension of Python) which supports working on graph structures in an intuitive manner.
Pygraphviz is a Python interface to the Graphviz graph layout and visualization package. With Pygraphviz you can create, edit, read, write, and draw graphs using Python to access the Graphviz graph data structure and layout algorithms.