Add Binary tree implementation

data-structures/binary_tree.py

@@ -0,0 +1,45 @@
+class Node:
+"""Binary tree node."""
+    def __init__(self, data=None):
+        self.left = left
+        self.data = data
+        self.right = right
+
+    def __iter__(self):
+        """In-order traversal of the items."""
+        if self.left:
+            yield from self.left
+        if self.data:
+            yield self.data
+        if self.right:
+            yield from self.right
+
+    def insert(self, data):
+        if not self.data:
+            self.data = data
+        elif data < self.data:
+            if self.left is None:
+                self.left = Node(data)
+            else:
+                self.left.insert(data)
+        elif data > self.data:
+            if self.right is None:
+                self.right = Node(data)
+            else:
+                self.right.insert(data)
+
+    def search(self, val):
+        if val == self.data:
+            return self
+        elif val < self.data:
+            if self.left is None:
+                raise KeyError
+            else:
+                self.left.search(val)
+        elif val > self.data:
+            if self.right is None:
+                raise KeyError
+            else:
+                self.right.search(val)
+
+