Add Distance.__iter__() and Distance.__len__(), for convenience.

beets/autotag/match.py

@@ -210,6 +210,12 @@ class Distance(object):
     def __init__(self):
         self._penalties = {}
 
+    def __iter__(self):
+        return iter(self.sorted)
+
+    def __len__(self):
+        return len(self.sorted)
+
     def __sub__(self, other):
         return self.distance - other
 
@@ -344,6 +350,9 @@ class Distance(object):
             dist = self[key]
             if dist:
                 list_.append((dist, key))
+        # Convert distance into a negative float we can sort items in ascending
+        # order (for keys, when the penalty is equal) and still get the items
+        # with the biggest distance first.
         return sorted(list_, key=lambda (dist, key): (0-dist, key))
 
     def update(self, dist):
@@ -545,10 +554,10 @@ 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.sorted)
+    keys = set(key for _, key in min_dist)
     if isinstance(results[0], hooks.AlbumMatch):
         for track_dist in min_dist.tracks.values():
-            keys.update(key for _, key in track_dist.sorted)
+            keys.update(key for _, key in track_dist)
     for key in keys:
         max_rec = config['match']['max_rec'][key].as_choice({
             'strong': recommendation.strong,
@@ -580,7 +589,7 @@ def _add_candidate(items, results, info):
     dist = distance(items, info, mapping)
 
     # Skip matches with ignored penalties.
-    penalties = [key for _, key in dist.sorted]
+    penalties = [key for _, key in dist]
     for penalty in config['match']['ignored'].as_str_seq():
         if penalty in penalties:
             log.debug('Ignored. Penalty: %s' % penalty)

beets/ui/commands.py

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

test/test_autotag.py

@@ -200,6 +200,23 @@ class DistanceTest(unittest.TestCase):
         self.dist.add('medium', 0.0)
         self.assertEqual(self.dist.max_distance, 5.0)
 
+    def test_operators(self):
+        config['match']['distance_weights']['source'] = 1.0
+        config['match']['distance_weights']['album'] = 2.0
+        config['match']['distance_weights']['medium'] = 1.0
+        self.dist.add('source', 0.0)
+        self.dist.add('album', 0.5)
+        self.dist.add('medium', 0.25)
+        self.dist.add('medium', 0.75)
+        self.assertEqual(len(self.dist), 2)
+        self.assertEqual(list(self.dist), [(0.2, 'album'), (0.2, 'medium')])
+        self.assertTrue(self.dist == 0.4)
+        self.assertTrue(self.dist < 1.0)
+        self.assertTrue(self.dist > 0.0)
+        self.assertEqual(self.dist - 0.4, 0.0)
+        self.assertEqual(0.4 - self.dist, 0.0)
+        self.assertEqual(float(self.dist), 0.4)
+
     def test_raw_distance(self):
         config['match']['distance_weights']['album'] = 3.0
         config['match']['distance_weights']['medium'] = 1.0