We can reproduce the same topology graph as before using the Python Graphviz package which we have installed:

$ python3
Python 3.5.2 (default, Nov 17 2016, 17:05:23)
>>> from graphviz import Digraph
>>> my_graph = Digraph(comment="My Network")
>>> my_graph.node("core")
>>> my_graph.node("distribution")
>>> my_graph.node("access1")
>>> my_graph.node("access2")
>>> my_graph.edge("core", "distribution")
>>> my_graph.edge("distribution", "access1")
>>> my_graph.edge("distribution", "access2")

The code basically produces what you would normally write in the DOT language but in a more Pythonic way. You can view the source of the graph before the graph generation:

>>> print(my_graph.source)
// My Network
digraph {
        core
        distribution
        access1
        access2
                core -> distribution
                distribution -> access1
                distribution -> access2
} 

The graph can be rendered by the render() method; by default, the output format is PDF:

>>> my_graph.render("output/chapter8_gv_3.gv")
'output/chapter8_gv_3.gv.pdf'

The Python package wrapper closely mimics all the API options of Graphviz. You can find documentation about the options on the Graphviz Read the Docs website (http://graphviz.readthedocs.io/en/latest/index.html). You can also refer to the source code on GitHub for more information (https://github.com/xflr6/graphviz). We are now ready to use the tool to map out our network.