Merge pull request metabrainz#1832 from zas/guesstracknumbertitle

Refactor File._guess_tracknumber_and_title() and add tests

Author: zas

picard/file.py

@@ -253,12 +253,11 @@ def _copy_loaded_metadata(self, metadata, postprocessors=None):
         self.metadata.copy(metadata)
 
     def _guess_tracknumber_and_title(self, metadata):
-        if 'tracknumber' not in metadata or 'title' not in metadata:
-            tracknumber, title = tracknum_and_title_from_filename(self.base_filename)
-            if 'tracknumber' not in metadata:
-                metadata['tracknumber'] = tracknumber
-            if 'title' not in metadata:
-                metadata['title'] = title
+        missing = {'tracknumber', 'title'} - set(metadata)
+        if missing:
+            guessed = tracknum_and_title_from_filename(self.base_filename)
+            for m in missing:
+                metadata[m] = getattr(guessed, m)
 
     def copy_metadata(self, metadata, preserve_deleted=True):
         acoustid = self.metadata["acoustid_id"]

picard/util/__init__.py

@@ -12,7 +12,7 @@
 # Copyright (C) 2012, 2014-2015 Wieland Hoffmann
 # Copyright (C) 2013 Ionuț Ciocîrlan
 # Copyright (C) 2013-2014 Sophist-UK
-# Copyright (C) 2013-2014, 2018-2020 Laurent Monin
+# Copyright (C) 2013-2014, 2018-2021 Laurent Monin
 # Copyright (C) 2014 Johannes Dewender
 # Copyright (C) 2016 Rahul Raturi
 # Copyright (C) 2016 barami
@@ -410,6 +410,9 @@ def tracknum_from_filename(base_filename):
     return None
 
 
+GuessedFromFilename = namedtuple('GuessedFromFilename', ('tracknumber', 'title'))
+
+
 def tracknum_and_title_from_filename(base_filename):
     """Guess tracknumber and title from filename.
     Uses `tracknum_from_filename` to guess the tracknumber. The filename is used
@@ -427,7 +430,7 @@ def tracknum_and_title_from_filename(base_filename):
         if stripped_filename[:tnlen] == tracknumber:
             title = stripped_filename[tnlen:].lstrip()
 
-    return (tracknumber, title)
+    return GuessedFromFilename(tracknumber, title)
 
 
 def is_hidden(filepath):

test/test_file.py

@@ -3,7 +3,8 @@
 # Picard, the next-generation MusicBrainz tagger
 #
 # Copyright (C) 2018-2021 Philipp Wolfer
-# Copyright (C) 2019-2020 Laurent Monin
+# Copyright (C) 2019-2021 Laurent Monin
+# Copyright (C) 2021 Sophist-UK
 #
 # This program is free software; you can redistribute it and/or
 # modify it under the terms of the GNU General Public License
@@ -290,3 +291,50 @@ def test_make_filename_replace_leading_dots(self):
         self.assertEqual(
             os.path.realpath('/media/music/_somealbum/_sometitle.mp3'),
             filename)
+
+
+class FileGuessTracknumberAndTitleTest(PicardTestCase):
+    def setUp(self):
+        super().setUp()
+        self.set_config_values({
+            'guess_tracknumber_and_title': True,
+        })
+
+    def test_no_guess(self):
+        f = File('/somepath/01 somefile.mp3')
+        metadata = Metadata({
+            'album': 'somealbum',
+            'title': 'sometitle',
+            'tracknumber': '2',
+        })
+        f._guess_tracknumber_and_title(metadata)
+        self.assertEqual(metadata['tracknumber'], '2')
+        self.assertEqual(metadata['title'], 'sometitle')
+
+    def test_guess_title(self):
+        f = File('/somepath/01 somefile.mp3')
+        metadata = Metadata({
+            'album': 'somealbum',
+            'tracknumber': '2',
+        })
+        f._guess_tracknumber_and_title(metadata)
+        self.assertEqual(metadata['tracknumber'], '2')
+        self.assertEqual(metadata['title'], 'somefile')
+
+    def test_guess_tracknumber(self):
+        f = File('/somepath/01 somefile.mp3')
+        metadata = Metadata({
+            'album': 'somealbum',
+            'title': 'sometitle',
+        })
+        f._guess_tracknumber_and_title(metadata)
+        self.assertEqual(metadata['tracknumber'], '1')
+
+    def test_guess_title_tracknumber(self):
+        f = File('/somepath/01 somefile.mp3')
+        metadata = Metadata({
+            'album': 'somealbum',
+        })
+        f._guess_tracknumber_and_title(metadata)
+        self.assertEqual(metadata['tracknumber'], '1')
+        self.assertEqual(metadata['title'], 'somefile')

test/test_utils.py

@@ -7,7 +7,7 @@
 # Copyright (C) 2010-2011, 2014, 2018-2021 Philipp Wolfer
 # Copyright (C) 2012, 2014, 2018 Wieland Hoffmann
 # Copyright (C) 2013 Ionuț Ciocîrlan
-# Copyright (C) 2013-2014, 2018-2020 Laurent Monin
+# Copyright (C) 2013-2014, 2018-2021 Laurent Monin
 # Copyright (C) 2014, 2017 Sophist-UK
 # Copyright (C) 2016 Frederik “Freso” S. Olesen
 # Copyright (C) 2017 Sambhav Kothari
@@ -516,6 +516,11 @@ def test_returns_expected_tracknumber(self):
             result = tracknum_and_title_from_filename(filename)
             self.assertEqual(expected, result)
 
+    def test_namedtuple(self):
+        result = tracknum_and_title_from_filename('0000002 Foo.mp3')
+        self.assertEqual(result.tracknumber, '2')
+        self.assertEqual(result.title, 'Foo')
+
 
 class PatternAsRegexTest(PicardTestCase):