lib: Create a metadata parsing class

This will help make Track creation a bit easier

Signed-off-by: Anna Schumaker <Anna@NoWheyCreamery.com>

lib/metadata.py

@@ -0,0 +1,47 @@
+# Copyright 2021 (c) Anna Schumaker.
+import mutagen
+import re
+
+class Metadata:
+    def __init__(self, filepath):
+        self.path = filepath
+        self.file = None
+
+    def __enter__(self):
+        self.file = mutagen.File(self.path)
+        return self
+
+    def __exit__(self, exp_type, exp_value, traceback):
+        self.file = None
+        return exp_type == None
+
+    def album(self):
+        return self.file.get("album", [ "Unknown Album" ])[0]
+
+    def artist(self):
+        artist = self.file.get("artist", [ "Unknown Artist" ])
+        return self.file.get("albumartist", artist)[0]
+
+    def decade(self):
+        return (self.year() // 10) * 10
+
+    def discnumber(self):
+        return int(self.file.get("discnumber", [ 1 ])[0])
+
+    def genres(self):
+        genre = self.file.get("genre", [ "" ])[0]
+        return [ g.strip() for g in re.split(",|;|/|:", genre) ]
+
+    def length(self):
+        return int(self.file.info.length)
+
+    def title(self):
+        return self.file.get("title", [ "" ])[0]
+
+    def tracknumber(self):
+        return int(self.file.get("tracknumber", [ 0 ])[0])
+
+    def year(self):
+        year = self.file.get("date", [ "0" ])
+        year = self.file.get("originalyear", year)[0]
+        return int(re.match("\d+", year).group(0))

lib/test_metadata.py

@@ -0,0 +1,32 @@
+# Copyright 2021 (c) Anna Schumaker.
+from . import metadata
+import pathlib
+import unittest
+
+test_tracks  = pathlib.Path("./trier/Test Album")
+track_01 = test_tracks / "01 - Test Track.ogg"
+track_02 = test_tracks / "02 - Test {Disc 2}.ogg"
+
+class TestMetadata(unittest.TestCase):
+    def test_metadata_init(self):
+        mdf = metadata.Metadata(track_01)
+        self.assertEqual(mdf.path, track_01)
+        self.assertIsNone(mdf.file)
+
+    def test_metadata_track_01(self):
+        with metadata.Metadata(track_01) as mdf:
+            self.assertEqual(mdf.album(),  "Test Album")
+            self.assertEqual(mdf.artist(), "Test Artist")
+            self.assertEqual(mdf.decade(),  2010)
+            self.assertEqual(mdf.discnumber(), 1)
+            self.assertEqual(mdf.genres(), [ "Test" ])
+            self.assertEqual(mdf.length(), 10)
+            self.assertEqual(mdf.title(), "Test Track")
+            self.assertEqual(mdf.tracknumber(), 1)
+            self.assertEqual(mdf.year(), 2019)
+
+    def test_metadata_track_02(self):
+        with metadata.Metadata(track_02) as mdf:
+            self.assertEqual(mdf.artist(), "Test Album Artist")
+            self.assertEqual(mdf.genres(), [ "Test", "Genre", "List" ])
+            self.assertEqual(mdf.year(), 2019)