Data commit

Task/Stack/Python/stack-2.py

@@ -0,0 +1,11 @@
+from collections import deque
+
+class Stack:
+    def __init__(self):
+        self._items = deque()
+    def append(self, item):
+        self._items.append(item)
+    def pop(self):
+        return self._items.pop()
+    def __nonzero__(self):
+        return bool(self._items)