Answering a question on Quora: http://www.quora.com/JavaScript/Help-explain-this-Javascript-function

findSequence.py

import networkx as nx


def draw_graph(G):
    from matplotlib import pyplot
    pos = nx.graphviz_layout(G, prog='dot')
    labels = dict((n, '%d' % n) for n, d in G.nodes(data=True))
    edge_labels = dict(((u, v,), d['op']) for u, v, d in G.edges(data=True))
    nx.draw_networkx(G, pos=pos, labels=labels, node_size=1000,
                     width=2, node_color='white', edge_color='blue')
    nx.draw_networkx_edge_labels(G, pos=pos, edge_labels=edge_labels)
    pyplot.show()


def make_graph(levels):
    G = nx.DiGraph()
    G.add_node(1)
    leafs = [1]
    for level in xrange(levels):
        print level
        newleafs = []
        for node in leafs:
            right = node + 5
            left = node * 3
            G.add_edge(node, right, {"op": "+5"})
            G.add_edge(node, left, {"op": "*3"})
            newleafs.append(right)
            newleafs.append(left)
        leafs = newleafs

    draw_graph(G)

draw(3)
 

Where do you define the draw called on line 33?