Merge pull request #40 from nbro/iss39

Removed check for None in the search_by_value method of the heap ds

ands/ds/Heap.py

@@ -6,7 +6,7 @@
 
 Creation: July, 2015
 
-Last update: 28/08/16
+Updated: 21/01/2017
 
 Base abstract class to represent heaps.
 See `MinHeap` and `MaxHeap` if you want to instantiate heap objects.
@@ -151,9 +151,10 @@ def search_by_value(self, val) -> int:
         If `val` and the values in this heap are not comparable,
         the behaviour of this method is undefined.
 
+        By construction, HeapNode objects can't be initialized with None values,
+        but that field could also be set manually after creation.
+
         **Time Complexity:** O(n)."""
-        if val is None:
-            raise ValueError("val cannot be None.")
         for i, node in enumerate(self.heap):
             if node.value == val:
                 return i

tests/ds/test_MaxHeap.py

@@ -18,7 +18,6 @@
 
 
 class TestMaxHeap(unittest.TestCase):
-
     def test_empty_heap_creation(self):
         h = MaxHeap()
         self.assertTrue(is_max_heap(h))
@@ -221,15 +220,16 @@ def test_search(self):
         self.assertRaises(ValueError, h.search, None)
         self.assertTrue(is_max_heap(h))
 
-    def test_search_by_value(self):
+    def test_search_by_value_incompatible_values(self):
         ls = [28, 14, 12]
         h = MaxHeap(ls)
-
         self.assertRaises(Exception, h.search_by_value, HeapNode(14))
-        self.assertRaises(ValueError, h.search_by_value, None)
-
         self.assertTrue(is_max_heap(h))
 
+    def test_search_by_value(self):
+        ls = [28, 14, 12]
+        h = MaxHeap(ls)
+
         v = h.search_by_value(14)
         self.assertIn(v, range(0, len(ls)))
         self.assertEqual(h.size(), len(ls))

tests/ds/test_MinHeap.py

@@ -18,7 +18,6 @@
 
 
 class TestMinHeap(unittest.TestCase):
-
     def test_empty_heap_creation(self):
         h = MinHeap()
         self.assertTrue(is_min_heap(h))
@@ -218,9 +217,6 @@ def test_search_by_value_bad(self):
         self.assertRaises(Exception, h.search_by_value, HeapNode(13))
         self.assertTrue(is_min_heap(h))
 
-        self.assertRaises(ValueError, h.search_by_value, None)
-        self.assertTrue(is_min_heap(h))
-
     def test_search_by_value_default(self):
         ls = [28, 14, 12]
         h = MinHeap(ls)

tests/ds/test_MinMaxHeap.py

@@ -245,7 +245,3 @@ def test_index_of_min_and_max(self):
         self.assertEqual(h.index_of_max(7), -1)
         self.assertEqual(h.index_of_min(8), -1)
         self.assertEqual(h.index_of_max(8), -1)
-
-
-if __name__ == "__main__":
-    unittest.main(verbosity=2)