fix format error

codes/python/chapter_tree/binary_tree_dfs.py

@@ -1,10 +1,12 @@
 """
 File: binary_tree_dfs.py
-Created Time: 2022-11-25
-Author: Krahets (krahets@163.com)
+Created Time: 2022-12-20
+Author: a16su (lpluls001@gmail.com)
 """
 
 import sys, os.path as osp
+import typing
+
 sys.path.append(osp.dirname(osp.dirname(osp.abspath(__file__))))
 from include import *
 
@@ -12,42 +14,42 @@ from include import *
 result = []
 
 
-def preOrder(root):
-    """
-    前序遍历二叉树
-    """
+""" 前序遍历二叉树 """
+
+
+def pre_order(root: typing.Optional[TreeNode]):
     if root is None:
         return
 
     # 访问优先级：根结点 -> 左子树 -> 右子树
     result.append(root.val)
-    preOrder(root=root.left)
-    preOrder(root=root.right)
+    pre_order(root=root.left)
+    pre_order(root=root.right)
 
 
-def inOrder(root):
-    """
-    中序遍历二叉树
-    """
+""" 中序遍历二叉树 """
+
+
+def in_order(root: typing.Optional[TreeNode]):
     if root is None:
         return
 
     # 访问优先级：左子树 -> 根结点 -> 右子树
-    inOrder(root=root.left)
+    in_order(root=root.left)
     result.append(root.val)
-    inOrder(root=root.right)
+    in_order(root=root.right)
 
 
-def postOrder(root):
-    """
-    后序遍历二叉树
-    """
+""" 后序遍历二叉树 """
+
+
+def post_order(root: typing.Optional[TreeNode]):
     if root is None:
         return
 
     # 访问优先级：左子树 -> 右子树 -> 根结点
-    postOrder(root=root.left)
-    postOrder(root=root.right)
+    post_order(root=root.left)
+    post_order(root=root.right)
     result.append(root.val)
 
 
@@ -55,26 +57,24 @@ def postOrder(root):
 if __name__ == "__main__":
     # 初始化二叉树
     # 这里借助了一个从数组直接生成二叉树的函数
-    root = list_to_tree(
-        arr=[1, 2, 3, 4, 5, 6, 7, None, None, None, None, None, None, None, None]
-    )
+    root = list_to_tree(arr=[1, 2, 3, 4, 5, 6, 7, None, None, None, None, None, None, None, None])
     print("\n初始化二叉树\n")
     print_tree(root)
 
     # 前序遍历
-    result = []
-    preOrder(root)
+    result.clear()
+    pre_order(root)
     print("\n前序遍历的结点打印序列 = ", result)
     assert result == [1, 2, 4, 5, 3, 6, 7]
 
     # 中序遍历
-    result = []
-    inOrder(root)
+    result.clear()
+    in_order(root)
     print("\n中序遍历的结点打印序列 = ", result)
     assert result == [4, 2, 5, 1, 6, 3, 7]
 
     # 后序遍历
-    result = []
-    postOrder(root)
+    result.clear()
+    post_order(root)
     print("\n后序遍历的结点打印序列 = ", result)
-    assert result == [4, 5, 2, 6, 7, 3, 1]
+    assert result == [4, 5, 2, 6, 7, 3, 1]