refactor: Follow the PEP 585 Typing standard (#439)

* Follow the PEP 585 Typing standard

* Update list.py

codes/python/chapter_graph/graph_adjacency_list.py

@@ -10,10 +10,10 @@ from modules import *
 
 class GraphAdjList:
     """ 基于邻接表实现的无向图类 """
-    def __init__(self, edges: List[List[Vertex]]) -> None:
+    def __init__(self, edges: list[list[Vertex]]) -> None:
         """ 构造方法 """
         # 邻接表，key: 顶点，value：该顶点的所有邻接顶点
-        self.adj_list: Dict = {}
+        self.adj_list = dict[Vertex, Vertex]()
         # 添加所有顶点和边
         for edge in edges:
             self.add_vertex(edge[0])

codes/python/chapter_graph/graph_adjacency_matrix.py

@@ -11,14 +11,14 @@ from modules import *
 class GraphAdjMat:
     """ 基于邻接矩阵实现的无向图类 """
     # 顶点列表，元素代表“顶点值”，索引代表“顶点索引”
-    vertices: List[int] = []
+    vertices: list[int] = []
     # 邻接矩阵，行列索引对应“顶点索引”
-    adj_mat: List[List[int]] = []
+    adj_mat: list[list[int]] = []
 
-    def __init__(self, vertices: List[int], edges: List[List[int]]) -> None:
+    def __init__(self, vertices: list[int], edges: list[list[int]]) -> None:
         """ 构造方法 """
-        self.vertices: List[int] = []
-        self.adj_mat: List[List[int]] = []
+        self.vertices: list[int] = []
+        self.adj_mat: list[list[int]] = []
         # 添加顶点
         for val in vertices:
             self.add_vertex(val)
@@ -85,8 +85,8 @@ class GraphAdjMat:
 if __name__ == "__main__":
     """ 初始化无向图 """
     # 请注意，edges 元素代表顶点索引，即对应 vertices 元素索引
-    vertices: List[int] = [1, 3, 2, 5, 4]
-    edges: List[List[int]] = [[0, 1], [0, 3], [1, 2], [2, 3], [2, 4], [3, 4]]
+    vertices: list[int] = [1, 3, 2, 5, 4]
+    edges: list[list[int]] = [[0, 1], [0, 3], [1, 2], [2, 3], [2, 4], [3, 4]]
     graph = GraphAdjMat(vertices, edges)
     print("\n初始化后，图为")
     graph.print()

codes/python/chapter_graph/graph_bfs.py

@@ -7,17 +7,18 @@ Author: Krahets (krahets@163.com)
 import sys, os.path as osp
 sys.path.append(osp.dirname(osp.dirname(osp.abspath(__file__))))
 from modules import *
+from collections import deque
 from graph_adjacency_list import GraphAdjList
 
-def graph_bfs(graph: GraphAdjList, start_vet: Vertex) -> List[Vertex]:
+def graph_bfs(graph: GraphAdjList, start_vet: Vertex) -> list[Vertex]:
     """ 广度优先遍历 BFS """
     # 使用邻接表来表示图，以便获取指定顶点的所有邻接顶点
     # 顶点遍历序列
     res = []
     # 哈希表，用于记录已被访问过的顶点
-    visited = set([start_vet])
+    visited = set[Vertex]([start_vet])
     # 队列用于实现 BFS
-    que = collections.deque([start_vet])
+    que = deque[Vertex]([start_vet])
     # 以顶点 vet 为起点，循环直至访问完所有顶点
     while len(que) > 0:
         vet = que.popleft()  # 队首顶点出队

codes/python/chapter_graph/graph_dfs.py

@@ -9,7 +9,7 @@ sys.path.append(osp.dirname(osp.dirname(osp.abspath(__file__))))
 from modules import *
 from graph_adjacency_list import GraphAdjList
 
-def dfs(graph: GraphAdjList, visited: Set[Vertex], res: List[Vertex], vet: Vertex):
+def dfs(graph: GraphAdjList, visited: set[Vertex], res: list[Vertex], vet: Vertex):
     """ 深度优先遍历 DFS 辅助函数 """
     res.append(vet)     # 记录访问顶点
     visited.add(vet) # 标记该顶点已被访问
@@ -21,12 +21,12 @@ def dfs(graph: GraphAdjList, visited: Set[Vertex], res: List[Vertex], vet: Verte
         dfs(graph, visited, res, adjVet)
 
 # 使用邻接表来表示图，以便获取指定顶点的所有邻接顶点
-def graph_dfs(graph: GraphAdjList, start_vet: Vertex) -> List[Vertex]:
+def graph_dfs(graph: GraphAdjList, start_vet: Vertex) -> list[Vertex]:
     """ 深度优先遍历 DFS """
     # 顶点遍历序列
     res = []
     # 哈希表，用于记录已被访问过的顶点
-    visited = set()
+    visited = set[Vertex]()
     dfs(graph, visited, res, start_vet)
     return res