diff --git a/codes/python/chapter_stack_and_queue/array_queue.py b/codes/python/chapter_stack_and_queue/array_queue.py
index 0e173fe..c4284d8 100644
--- a/codes/python/chapter_stack_and_queue/array_queue.py
+++ b/codes/python/chapter_stack_and_queue/array_queue.py
@@ -1,6 +1,6 @@
 '''
 File: array_queue.py
-Created Time: 2022-11-29
+Created Time: 2022-12-01
 Author: Peng Chen (pengchzn@gmail.com)
 '''
 
@@ -13,22 +13,22 @@ from include import *
 """ 基于环形数组实现的队列 """
 class ArrayQueue:
     def __init__(self, size):
-        self.nums = [None] * size  # 用于存储队列元素的数组
-        self.front = 0  # 头指针，指向队首
-        self.rear = 0  # 尾指针，指向队尾 + 1
+        self.__nums = [None] * size  # 用于存储队列元素的数组
+        self.__front = 0  # 头指针，指向队首
+        self.__rear = 0  # 尾指针，指向队尾 + 1
 
     """ 获取队列的容量 """
     def capacity(self):
-        return len(self.nums)
+        return len(self.__nums)
 
     """ 获取队列的长度 """
     def size(self):
         # 由于将数组看作为环形，可能 rear < front ，因此需要取余数
-        return (self.capacity() + self.rear - self.front) % self.capacity()
+        return (self.capacity() + self.__rear - self.__front) % self.capacity()
 
     """ 判断队列是否为空 """
     def is_empty(self):
-        return len(self.nums)==0
+        return (self.__rear - self.__front) == 0
 
     """ 入队 """
     def put(self, val):
@@ -36,9 +36,9 @@ class ArrayQueue:
             print("队列已满")
             return False
         # 尾结点后添加 num
-        self.nums[self.rear] = val
+        self.__nums[self.__rear] = val
         # 尾指针向后移动一位，越过尾部后返回到数组头部
-        self.rear = (self.rear + 1) % self.capacity()
+        self.__rear = (self.__rear + 1) % self.capacity()
 
     """ 出队 """
     def get(self):
@@ -46,28 +46,39 @@ class ArrayQueue:
         if self.is_empty():
             print("队列为空")
             return False
-        num = self.nums[self.front]
-        self.nums[self.front] = None
+        num = self.__nums[self.__front]
         # 队头指针向后移动，越过尾部后返回到数组头部
-        self.front = (self.front + 1) % self.capacity()
+        self.__front = (self.__front + 1) % self.capacity()
         return num
 
     """ 访问队首元素 """
     def peek(self):
         # 删除头结点
         if self.is_empty():
-            return 1
-        return self.nums[self.front]
+            print("队列为空")
+            return False
+        return self.__nums[self.__front]
 
     """ 访问指定位置元素 """
     def get_index(self, index):
         if index >= self.size():
-            return -1
-        return self.nums[(self.front + index) % self.capacity()]
+            print("索引越界")
+            return False
+        return self.__nums[(self.__front + index) % self.capacity()]
+
+    """ 返回列表用于打印 """
+    def to_list(self):
+        res = [None] * self.size()
+        j = self.__front
+        for i in range(self.size()):
+            res[i] = self.__nums[(j % self.capacity())]
+            j += 1
+        return res
+
 
 if __name__ == "__main__":
     """ 初始化队列 """
-    queue = ArrayQueue(5)
+    queue = ArrayQueue(10)
 
     """ 元素入队 """
     queue.put(1)
@@ -75,16 +86,20 @@ if __name__ == "__main__":
     queue.put(2)
     queue.put(5)
     queue.put(4)
-    print("队列 queue = ", queue.nums)
+    print("队列 queue = ", queue.to_list())
 
     """ 访问队首元素 """
     peek = queue.peek()
     print("队首元素 peek = ", peek)
 
+    """ 访问索引 index 处元素 """
+    num = queue.get_index(3)
+    print("队列索引 3 处的元素为 num =", num)
+
     """ 元素出队 """
     get = queue.get()
     print("出队元素 get = ", get)
-    print("出队后 queue = ", queue.nums)
+    print("出队后 queue = ", queue.to_list())
 
     """ 获取队列的长度 """
     size = queue.size()
diff --git a/codes/python/chapter_stack_and_queue/deque.py b/codes/python/chapter_stack_and_queue/deque.py
index 0bddd0d..a2929df 100644
--- a/codes/python/chapter_stack_and_queue/deque.py
+++ b/codes/python/chapter_stack_and_queue/deque.py
@@ -38,10 +38,10 @@ if __name__ == "__main__":
     print("队尾出队元素  popLast= ", popLast)
     print("队尾出队后 duque = ", duque)
 
-    """ 获取队列的长度 """
+    """ 获取双向队列的长度 """
     size = len(duque)
-    print("队列长度 size = ", size)
+    print("双向队列长度 size = ", size)
 
-    """ 判断队列是否为空 """
+    """ 判断双向队列是否为空 """
     is_empty = len(duque) == 0
-    print("队列是否为空 = ", is_empty)
+    print("双向队列是否为空 = ", is_empty)
diff --git a/codes/python/chapter_stack_and_queue/linkedlist_queue.py b/codes/python/chapter_stack_and_queue/linkedlist_queue.py
index 53f3b9a..d5a2202 100644
--- a/codes/python/chapter_stack_and_queue/linkedlist_queue.py
+++ b/codes/python/chapter_stack_and_queue/linkedlist_queue.py
@@ -1,6 +1,6 @@
 '''
 File: linkedlist_queue.py
-Created Time: 2022-11-29
+Created Time: 2022-12-01
 Author: Peng Chen (pengchzn@gmail.com)
 '''
 
@@ -50,10 +50,12 @@ class LinkedListQueue:
     """ 访问队首元素 """
     def peek(self):
         if self.size() == 0:
-            return -1
+            print("队列为空")
+            return False
         return self.__front.val
 
-    def to_array(self):
+    """ 转化为列表用于打印 """
+    def to_list(self):
         queue = []
         temp = self.__front
         while temp:
@@ -72,7 +74,7 @@ if __name__ == "__main__":
     queue.put(2)
     queue.put(5)
     queue.put(4)
-    print("队列 queue = ", queue.to_array())
+    print("队列 queue = ", queue.to_list())
 
     """ 访问队首元素 """
     peek = queue.peek()
@@ -81,7 +83,7 @@ if __name__ == "__main__":
     """ 元素出队 """
     get = queue.get()
     print("出队元素 get = ", get)
-    print("出队后 queue = ", queue.to_array())
+    print("出队后 queue = ", queue.to_list())
 
     """ 获取队列的长度 """
     size = queue.size()