Update python code of stack.

codes/python/chapter_stack_and_queue/array_stack.py

@@ -4,46 +4,45 @@ Created Time: 2022-11-29
 Author: Peng Chen (pengchzn@gmail.com)
 '''
 
-import os.path as osp
-import sys
-
+import sys, os.path as osp
 sys.path.append(osp.dirname(osp.dirname(osp.abspath(__file__))))
 from include import *
 
 """ 基于数组实现的栈 """
 class ArrayStack:
     def __init__(self):
-        self._stack = []
-        self._size = 0
+        self.__stack = []
 
     """ 获取栈的长度 """
     def size(self):
-        return self._size
+        return len(self.__stack)
 
     """ 判断栈是否为空 """
     def is_empty(self):
-        return self._stack == []
+        return self.__stack == []
 
     """ 入栈 """
     def push(self, item):
-        self._stack.append(item)
-        self._size += 1
+        self.__stack.append(item)
 
     """ 出栈 """
     def pop(self):
-        pop = self._stack.pop()
-        self._size -= 1
-        return pop
+        return self.__stack.pop()
 
     """ 访问栈顶元素 """
     def peek(self):
-        return self._stack[-1]
+        return self.__stack[-1]
 
     """ 访问索引 index 处元素 """
     def get(self, index):
-        return self._stack[index]
+        return self.__stack[index]
+    
+    """ 返回列表用于打印 """
+    def toList(self):
+        return self.__stack
 
 
+""" Driver Code """
 if __name__ == "__main__":
     """ 初始化栈 """
     stack = ArrayStack()
@@ -54,20 +53,20 @@ if __name__ == "__main__":
     stack.push(2)
     stack.push(5)
     stack.push(4)
-    print("栈 stack = ", stack._stack)
+    print("栈 stack =", stack.toList())
 
     """ 访问栈顶元素 """
     peek = stack.peek()
-    print("栈顶元素 peek = ", peek)
+    print("栈顶元素 peek =", peek)
 
     """ 元素出栈 """
     pop = stack.pop()
-    print("出栈元素 pop = ", pop)
-    print("出栈后 stack = ", stack._stack)
+    print("出栈元素 pop =", pop)
+    print("出栈后 stack =", stack.toList())
 
     """ 获取栈的长度 """
     size = stack.size()
-    print("栈的长度 size = ", size)
+    print("栈的长度 size =", size)
 
     """ 判断是否为空 """
     isEmpty = stack.is_empty()