Added basic graph implementation challenge.

graphs_trees/graph/test_graph.py

@@ -0,0 +1,39 @@
+from nose.tools import assert_equal
+
+
+class TestGraph(object):
+
+    def test_graph(self):
+        graph = Graph()
+        for key in range(0, 6):
+            graph.add_node(key)
+        graph.add_edge(0, 1, 5)
+        graph.add_edge(0, 5, 2)
+        graph.add_edge(1, 2, 3)
+        graph.add_edge(2, 3, 4)
+        graph.add_edge(3, 4, 5)
+        graph.add_edge(3, 5, 6)
+        graph.add_edge(4, 0, 7)
+        graph.add_edge(5, 4, 8)
+        graph.add_edge(5, 2, 9)
+
+        assert_equal(graph.nodes[0].connections[graph.nodes[1]], 5)
+        assert_equal(graph.nodes[0].connections[graph.nodes[5]], 2)
+        assert_equal(graph.nodes[1].connections[graph.nodes[2]], 3)
+        assert_equal(graph.nodes[2].connections[graph.nodes[3]], 4)
+        assert_equal(graph.nodes[3].connections[graph.nodes[4]], 5)
+        assert_equal(graph.nodes[3].connections[graph.nodes[5]], 6)
+        assert_equal(graph.nodes[4].connections[graph.nodes[0]], 7)
+        assert_equal(graph.nodes[5].connections[graph.nodes[4]], 8)
+        assert_equal(graph.nodes[5].connections[graph.nodes[2]], 9)
+
+        print('Success: test_graph')
+
+
+def main():
+    test = TestGraph()
+    test.test_graph()
+
+
+if __name__ == '__main__':
+    main()