Draw a DAG with `graphviz` python api

graphviz_dag.py

# Simple example of using graphviz to draw DAGs while working in a jupyter notebook environment
import graphviz as gr

# Simple DAG with a confounder
h = gr.Digraph('Simple DAG with confounder')
h.edge('Treatment', 'Outcome')
h.edge('Confounder', 'Treatment')
h.edge('Confounder', 'Outcome')
display(h)


# Regression Example
g = gr.Digraph('Regression with subgraph')
g.edge('alpha', 'mu')
g.edge('beta', 'mu')

#subgraph name must begin with 'cluster'
with g.subgraph(name='cluster') as c:
    c.attr(label='N', labeljust='r', labelloc='b')
    c.edges([('mu', 'y'), ('sigma', 'y')])
    c.node('y', label='obs', style='filled')
display(g)

'hello world' examples of using the python graphviz library to create simple DAGs while in jupyter notebook.