Update array_stack.py

An type error of ";"

codes/python/chapter_stack_and_queue/array_stack.py

@@ -60,8 +60,8 @@ if __name__ == "__main__":
     print("栈顶元素 peek =", peek)
 
     """ 访问索引 index 处元素 """
-    num = stack.get(3);
-    print("栈索引 3 处的元素为 num =", num);
+    num = stack.get(3)
+    print("栈索引 3 处的元素为 num =", num)
 
     """ 元素出栈 """
     pop = stack.pop()