add keys() method to Distance

beets/autotag/hooks.py

@@ -267,7 +267,7 @@ class Distance(object):
 
     @property
     def distance(self):
-        """Returns a weighted and normalised distance across all
+        """Return a weighted and normalized distance across all
         penalties.
         """
         dist_max = self.max_distance
@@ -277,7 +277,7 @@ class Distance(object):
 
     @property
     def max_distance(self):
-        """Returns the maximum distance penalty.
+        """Return the maximum distance penalty (normalization factor).
         """
         dist_max = 0.0
         for key, penalty in self._penalties.iteritems():
@@ -286,16 +286,15 @@ class Distance(object):
 
     @property
     def raw_distance(self):
-        """Returns the raw (denormalized) distance.
+        """Return the raw (denormalized) distance.
         """
         dist_raw = 0.0
         for key, penalty in self._penalties.iteritems():
             dist_raw += sum(penalty) * self._weights[key]
         return dist_raw
 
-    @property
     def items(self):
-        """Returns a list of (key, dist) pairs, with `dist` being the
+        """Return a list of (key, dist) pairs, with `dist` being the
         weighted distance, sorted from highest to lowest. Does not
         include penalties with a zero value.
         """
@@ -336,10 +335,13 @@ class Distance(object):
         return 0.0
 
     def __iter__(self):
-        return iter(self.items)
+        return iter(self.items())
 
     def __len__(self):
-        return len(self.items)
+        return len(self.items())
+
+    def keys(self):
+        return [key for key, _ in self.items()]
 
     def update(self, dist):
         """Adds all the distance penalties from `dist`.

beets/autotag/match.py

@@ -291,10 +291,10 @@ def _recommendation(results):
 
     # Downgrade to the max rec if it is lower than the current rec for an
     # applied penalty.
-    keys = set(key for key, _ in min_dist)
+    keys = set(min_dist.keys())
     if isinstance(results[0], hooks.AlbumMatch):
         for track_dist in min_dist.tracks.values():
-            keys.update(key for key, _ in track_dist)
+            keys.update(track_dist.keys())
     for key in keys:
         max_rec = config['match']['max_rec'][key].as_choice({
             'strong': recommendation.strong,

beets/ui/commands.py

@@ -168,7 +168,7 @@ def penalty_string(distance, limit=None):
     applied to a distance object.
     """
     penalties = []
-    for key, _ in distance:
+    for key in distance.keys():
         key = key.replace('album_', '')
         key = key.replace('track_', '')
         key = key.replace('_', ' ')

test/test_autotag.py

@@ -239,7 +239,7 @@ class DistanceTest(_common.TestCase):
         dist = Distance()
         dist.add('album', 0.1875)
         dist.add('medium', 0.75)
-        self.assertEqual(dist.items, [('medium', 0.25), ('album', 0.125)])
+        self.assertEqual(dist.items(), [('medium', 0.25), ('album', 0.125)])
 
         # Sort by key if distance is equal.
         dist = Distance()