update from Atlas

13-op-overloading/bingoaddable.py

@@ -0,0 +1,59 @@
+"""
+======================
+AddableBingoCage tests
+======================
+
+
+Tests for __add__ and __iadd__:
+
+    >>> vowels = 'AEIOU'
+    >>> globe = AddableBingoCage(vowels)
+    >>> len(globe)
+    5
+    >>> globe.pop() in vowels
+    True
+    >>> len(globe)
+    4
+    >>> globe2 = AddableBingoCage('XYZ')
+    >>> globe3 = globe + globe2
+    >>> len(globe3)
+    7
+    >>> void = globe + [10, 20]
+    Traceback (most recent call last):
+      ...
+    TypeError: unsupported operand type(s) for +: 'AddableBingoCage' and 'list'
+
+
+Tests for __add__ and __iadd__:
+
+    >>> globe_orig = globe
+    >>> len(globe)
+    4
+    >>> globe += globe2
+    >>> len(globe)
+    7
+    >>> globe += [10, 20]
+    >>> len(globe)
+    9
+    >>> globe is globe_orig
+    True
+
+"""
+
+# BEGIN ADDABLE_BINGO
+import itertools  # <1>
+from bingobase import BingoCage
+
+
+class AddableBingoCage(BingoCage):  # <2>
+
+    def __add__(self, other):
+        if isinstance(other, AddableBingoCage):  # <3>
+            return AddableBingoCage(itertools.chain(self, other))  # <4>
+        else:
+            return NotImplemented
+
+    def __iadd__(self, other):
+        self.load(other)  # <5>
+        return self  # <6>
+# END ADDABLE_BINGO