all tasks

Task/Stack/Python/stack-1.py

@@ -0,0 +1,5 @@
+from collections import deque
+stack = deque()
+stack.append(value) # pushing
+value = stack.pop()
+not stack # is empty?

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)

Task/Stack/Python/stack-3.py

@@ -0,0 +1,12 @@
+class Stack:
+    def __init__(self):
+        self._first = None
+    def __nonzero__(self):
+        return self._first is not None
+    def append(self, value):
+        self._first = (value, self._first)
+    def pop(self):
+        if self._first is None:
+            raise IndexError, "pop from empty stack"
+        value, self._first = self._first
+        return value

Task/Stack/Python/stack-4.py

@@ -0,0 +1 @@
+while not stack.empty():

Task/Stack/Python/stack-5.py

@@ -0,0 +1 @@
+while stack: