Plots the reverse dependences of a FreeBSD package, cleaned up to remove redundant edges

pkg_graph.py

import subprocess
import networkx as nx
import matplotlib.pyplot as plt

from sys import argv

root = argv[1]

G = nx.DiGraph()

processed = []

def simplify(s):
    return "-".join(s.split("-")[:-1]) + " "*8

def branches(depth, pkg):
    if pkg not in processed:
        processed.append(pkg)
        print depth, pkg
        for i in subprocess.check_output(
                [ "pkg", "query", "%rn-%rv", pkg ]).splitlines():
            G.add_edge(simplify(pkg), simplify(i))
            branches(depth + 1, i)

branches(0, root)

# TODO check fetching two entries from the generator
def not_unique(gen):
    return len(list(gen)) > 1

for (p,q) in G.edges():
    if not_unique(nx.all_simple_paths(G, source=p, target=q)):
        G.remove_edge(p,q)

pos=nx.graphviz_layout(G, prog="dot")
nx.draw(G, pos,
        node_size=0, alpha=0.2, edge_color='r', font_size=9)
plt.show()