Fix Python code.

codes/python/chapter_stack_and_queue/array_queue.py

@@ -10,53 +10,53 @@ class ArrayQueue:
 
     def __init__(self, size: int):
         """构造方法"""
-        self.__nums: list[int] = [0] * size  # 用于存储队列元素的数组
-        self.__front: int = 0  # 队首指针，指向队首元素
-        self.__size: int = 0  # 队列长度
+        self._nums: list[int] = [0] * size  # 用于存储队列元素的数组
+        self._front: int = 0  # 队首指针，指向队首元素
+        self._size: int = 0  # 队列长度
 
     def capacity(self) -> int:
         """获取队列的容量"""
-        return len(self.__nums)
+        return len(self._nums)
 
     def size(self) -> int:
         """获取队列的长度"""
-        return self.__size
+        return self._size
 
     def is_empty(self) -> bool:
         """判断队列是否为空"""
-        return self.__size == 0
+        return self._size == 0
 
     def push(self, num: int):
         """入队"""
-        if self.__size == self.capacity():
+        if self._size == self.capacity():
             raise IndexError("队列已满")
         # 计算尾指针，指向队尾索引 + 1
         # 通过取余操作，实现 rear 越过数组尾部后回到头部
-        rear: int = (self.__front + self.__size) % self.capacity()
+        rear: int = (self._front + self._size) % self.capacity()
         # 将 num 添加至队尾
-        self.__nums[rear] = num
-        self.__size += 1
+        self._nums[rear] = num
+        self._size += 1
 
     def pop(self) -> int:
         """出队"""
         num: int = self.peek()
         # 队首指针向后移动一位，若越过尾部则返回到数组头部
-        self.__front = (self.__front + 1) % self.capacity()
-        self.__size -= 1
+        self._front = (self._front + 1) % self.capacity()
+        self._size -= 1
         return num
 
     def peek(self) -> int:
         """访问队首元素"""
         if self.is_empty():
             raise IndexError("队列为空")
-        return self.__nums[self.__front]
+        return self._nums[self._front]
 
     def to_list(self) -> list[int]:
         """返回列表用于打印"""
         res = [0] * self.size()
-        j: int = self.__front
+        j: int = self._front
         for i in range(self.size()):
-            res[i] = self.__nums[(j % self.capacity())]
+            res[i] = self._nums[(j % self.capacity())]
             j += 1
         return res