Add typing annotations to Python codes. (#411)

codes/python/chapter_array_and_linkedlist/list.py

@@ -12,11 +12,11 @@ from modules import *
 """ Driver Code """
 if __name__ == "__main__":
     """ 初始化列表 """
-    list = [1, 3, 2, 5, 4]
+    list: List[int] = [1, 3, 2, 5, 4]
     print("列表 list =", list)
 
     """ 访问元素 """
-    num = list[1]
+    num: int = list[1]
     print("访问索引 1 处的元素，得到 num =", num)
 
     """ 更新元素 """
@@ -44,17 +44,17 @@ if __name__ == "__main__":
     print("删除索引 3 处的元素，得到 list =", list)
 
     """ 通过索引遍历列表 """
-    count = 0
+    count: int = 0
     for i in range(len(list)):
         count += 1
 
     """ 直接遍历列表元素 """
-    count = 0
+    count: int = 0
     for n in list:
         count += 1
 
     """ 拼接两个列表 """
-    list1 = [6, 8, 7, 10, 9]
+    list1: List[int] = [6, 8, 7, 10, 9]
     list += list1
     print("将列表 list1 拼接到 list 之后，得到 list =", list)