Add the code to the docs.

codes/python/chapter_tree/binary_tree.py

@@ -12,13 +12,14 @@ from include import *
 
 """ Driver Code """
 if __name__ == "__main__":
-    # 初始化二叉树
+    """ 初始化二叉树 """
     # 初始化节点
     n1 = TreeNode(val=1)
     n2 = TreeNode(val=2)
     n3 = TreeNode(val=3)
     n4 = TreeNode(val=4)
     n5 = TreeNode(val=5)
+    # 构建引用指向（即指针）
     n1.left = n2
     n1.right = n3
     n2.left = n4
@@ -26,15 +27,13 @@ if __name__ == "__main__":
     print("\n初始化二叉树\n")
     print_tree(n1)
 
-    # 插入与删除结点
+    """ 插入与删除结点 """
     P = TreeNode(0)
-
     # 在 n1 -> n2 中间插入节点 P
     n1.left = P
     P.left = n2
     print("\n插入结点 P 后\n")
     print_tree(n1)
-
     # 删除结点
     n1.left = n2
     print("\n删除结点 P 后\n");