Added binary_tree_traversal.py

Author: VarunS2002

binary_tree_traversal.py

@@ -0,0 +1,81 @@
+from typing import Optional
+
+
+class Node:
+    def __init__(self, key: Optional[float]) -> None:
+        self._left: Optional[Node] = None
+        self._right: Optional[Node] = None
+        self._value: Optional[float] = key
+
+    def display(self) -> None:
+        if self._left:
+            self._left.display()
+        print(self._value, end=' ')
+        if self._right:
+            self._right.display()
+
+    def display_preorder(self) -> None:
+        if self._value:
+            print(self._value, end=' ')
+            if self._left:
+                self._left.display_preorder()
+            if self._right:
+                self._right.display_preorder()
+
+    def display_inorder(self) -> None:
+        if self._value:
+            if self._left:
+                self._left.display_inorder()
+            print(self._value, end=' ')
+            if self._right:
+                self._right.display_inorder()
+
+    def display_postorder(self) -> None:
+        if self._value:
+            if self._left:
+                self._left.display_postorder()
+            if self._right:
+                self._right.display_postorder()
+            print(self._value, end=' ')
+
+    def insert(self, data: float) -> None:
+        if self._value:
+            if data < self._value:
+                if self._left is None:
+                    self._left = Node(data)
+                else:
+                    self._left.insert(data)
+            elif data > self._value:
+                if self._right is None:
+                    self._right = Node(data)
+                else:
+                    self._right.insert(data)
+        else:
+            self._value = data
+
+
+if __name__ == '__main__':
+    root = Node(10)
+    root._left = Node(12)
+    root._right = Node(5)
+    print("Without any order")
+    root.display()
+    print()
+    root_1 = Node(None)
+    root_1.insert(28)
+    root_1.insert(4)
+    root_1.insert(13)
+    root_1.insert(130)
+    root_1.insert(123)
+    print("Now ordering with insert")
+    root_1.display()
+    print()
+    print("Pre order")
+    root_1.display_preorder()
+    print()
+    print("In Order")
+    root_1.display_inorder()
+    print()
+    print("Post Order")
+    root_1.display_postorder()
+    print()