Basic implementation of a DisjointSet in Python, tests.

disjoint_set_test.py

import unittest
from disjoint_set import DisjointSet

class DisjointSetTest(unittest.TestCase):
    def test_connectedness(self):
        ds = DisjointSet(5)
        self.assertFalse(ds.connected(0, 4))
        ds.connect(0, 4)
        self.assertTrue(ds.connected(0, 4))

        self.assertFalse(ds.connected(2, 3))
        ds.connect(2, 3)
        self.assertTrue(ds.connected(2, 3))
        ds.connect(3, 4)
        self.assertTrue(ds.connected(0, 2))

if __name__ == '__main__':
    unittest.main()