update from Atlas with major reorg

13-op-overloading/bingo.py

@@ -0,0 +1,28 @@
+# BEGIN TOMBOLA_BINGO
+
+import random
+
+from tombola import Tombola
+
+
+class BingoCage(Tombola):  # <1>
+
+    def __init__(self, items):
+        self._randomizer = random.SystemRandom()  # <2>
+        self._items = []
+        self.load(items)  # <3>
+
+    def load(self, items):
+        self._items.extend(items)
+        self._randomizer.shuffle(self._items)  # <4>
+
+    def pick(self):  # <5>
+        try:
+            return self._items.pop()
+        except IndexError:
+            raise LookupError('pick from empty BingoCage')
+
+    def __call__(self):  # <7>
+        self.pick()
+
+# END TOMBOLA_BINGO