Graph implementation experiments.

graph.py

#!/usr/bin/python
from collections import defaultdict
import user
import random

class Graph:
  def __init__(self):
    self._vertices = set()
    self._edges = defaultdict(list)
  def add_vertex(self, data):
    print 'adding vertex', data
    self._vertices.add(data)
  def add_edge(self, data1, data2, cost, reverse=True):
    print 'adding egde,', data1, data2, cost
    if not data1 in self._vertices: raise Exception("no such vertex %s", data1)
    if not data2 in self._vertices: raise Exception("no such vertex %s", data2)
    self._edges[data1].append((data2, cost, ))
    if reverse:
      self.add_edge(data2, data1, cost, reverse=False)
  def edges(self, data):
    return self._edges[data]
  def to_dot(self):
    x = "digraph G { \n"
    for f, es in self._edges.iteritems():
      for e in es:
        t, c = e
        x += "    %s -> %s [label=%s];\n" % (f, t, c)
    x += "}"
    return x

g = Graph()

# vertices
CARDS = [chr(x) for x in range(ord('A'), ord('G') + 1)]

# so we can use random.choice, FIXME.
COSTS = range(1, 101)

for x in CARDS: g.add_vertex(x)
for i in range(1, 10):
  g.add_edge(random.choice(CARDS), random.choice(CARDS), random.choice(COSTS),
      reverse=False)

# write out the graphviz file
with open('/tmp/g.gv', 'w+') as f:
  f.write(g.to_dot())