JosephSalisbury · November 19, 2014 15:39 · Nov 19, 2014
diff --git a/fill b/fill
@@ -0,0 +1,36 @@
+""" Fill up a container, to some numerical limit, from another container
+    dependent on some predicate between the item and the dependent
+    container. """
+
+from itertools import takewhile
+import unittest
+
+
+def fill(source, destination, limit, predicate):
+
+    iterator = source.__iter__()
+
+    while len(destination) != limit:
+        item = iterator.next()
+
+        if predicate(destination, item):
+            destination.append(item)
+
+class TestUniqueFill(unittest.TestCase):
+
+    def setUp(self):
+
+        self.source = ['a', 'c', 'a', 'b', 'a', 'c', 'd']
+        self.destination = []
+
+    def test_fill(self):
+
+        fill(self.source, self.destination, 3, lambda d, i: i not in d)
+
+        self.assertEquals(
+            self.destination,
+            ['a', 'c', 'b']
+        )
+
+if __name__ == "__main__":
+    unittest.main()