Toy example for networkx python graph package

networkx_example.py

import networkx as nx

# pip install networkx

# directed graph example using networkx as a graph engine

G = nx.DiGraph()

roots = set()

roots.add('cl')

G.add_edge('cl', 'dl')
G.add_edge('dl', 'ip')
G.add_edge('cl', 'ip')
G.add_edge('dl', 'mp')
G.add_edge('cl', 'mp')
G.add_edge('mp', 'hs')


for r in roots:
    print "root %s" % r    
    spacer = {r: 0}
    for prereq, target in nx.dfs_edges(G, r):
        spacer[target] = spacer[prereq] + 2
        print '{spacer}+-{t}'.format(
            spacer=' ' * spacer[prereq],
            t=target)
    print ''


for np in G:
    for pred in G.predecessors(np):
        print "pred %s" % pred
    print "next %s" % np