random number generator. Altered it a bit to use the old generator
and restore the test.
>>> roots = sets[:]
>>> import random
->>> random.seed(42)
+>>> gen = random.WichmannHill(42)
>>> while 1:
... for s in sets:
... print "%s->%s" % (s, s.find()),
... print
... if len(roots) > 1:
-... s1 = random.choice(roots)
+... s1 = gen.choice(roots)
... roots.remove(s1)
-... s2 = random.choice(roots)
+... s2 = gen.choice(roots)
... s1.union(s2)
... print "merged", s1, "into", s2
... else: