added some recursive datastructures

recursion/recursive_datastructure/solution/test_trees.py

@@ -0,0 +1,13 @@
+from trees import Node, traverse, TraversalType
+
+
+def test_traverse():
+    tree = Node(1, Node(2, Node(3, None, None), Node(4, Node(
+        5, None, None), None)), Node(6, Node(7, None, None), Node(8, None, None)))
+
+    assert ", ".join(map(lambda x: str(x), traverse(tree))
+                     ) == "3, 2, 5, 4, 1, 7, 6, 8"
+    assert ", ".join(map(lambda x: str(x), traverse(
+        tree, TraversalType.PREORDER))) == "1, 2, 3, 4, 5, 6, 7, 8"
+    assert ", ".join(map(lambda x: str(x), traverse(
+        tree, TraversalType.POSTORDER))) == "3, 5, 4, 2, 7, 8, 6, 1"