Added unique utility method.

benedict/dicts/__init__.py

@@ -98,3 +98,6 @@ class benedict(IODict, KeypathDict, ParseDict):
 
     def swap(self, key1, key2):
         dict_util.swap(self, key1, key2)
+
+    def unique(self):
+        dict_util.unique(self)

benedict/utils/dict_util.py

@@ -110,3 +110,14 @@ def subset(d, keys, *args):
 
 def swap(d, key1, key2):
     d[key1], d[key2] = d[key2], d[key1]
+
+
+def unique(d):
+    values = []
+    keys = sorted(d.keys())
+    for key in keys:
+        value = d.get(key, None)
+        if value in values:
+            d.pop(key, None)
+            continue
+        values.append(value)

tests/test_benedict.py

@@ -1194,3 +1194,52 @@ class BenedictTestCase(unittest.TestCase):
             },
         }
         self.assertEqual(b, r)
+
+    def test_unique(self):
+        d = {
+            'a': {
+                'x': 1,
+                'y': 1,
+            },
+            'b': {
+                'x': 2,
+                'y': 2,
+            },
+            'c': {
+                'x': 1,
+                'y': 1,
+            },
+            'd': {
+                'x': 1,
+            },
+            'e': {
+                'x': 1,
+                'y': 1,
+                'z': 1,
+            },
+            'f': {
+                'x': 2,
+                'y': 2,
+            },
+        }
+        b = benedict(d)
+        b.unique()
+        r = {
+            'a': {
+                'x': 1,
+                'y': 1,
+            },
+            'b': {
+                'x': 2,
+                'y': 2,
+            },
+            'd': {
+                'x': 1,
+            },
+            'e': {
+                'x': 1,
+                'y': 1,
+                'z': 1,
+            },
+        }
+        self.assertEqual(b, r)