tools: Add a script for finding what files are missing a tag

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

tools/missing_tag.py

@@ -0,0 +1,43 @@
+#!/usr/bin/python
+# Copyright 2020 (c) Anna Schumaker
+#
+# Use Mutagen to generate a list of tracks missing a specific tag for
+# all music files in the requested directory
+import mutagen
+import os
+import pathlib
+import sys
+
+if len(sys.argv) != 3 or not os.path.isdir(sys.argv[2]):
+    print(f"Usage: {sys.argv[0]} TAG DIRECTORY")
+    sys.exit(1)
+
+print()
+print(f"Reading directory {sys.argv[2]}:")
+
+files  = [ ]
+for entry in pathlib.Path(sys.argv[2]).rglob("*"):
+    if os.path.isfile(entry):
+        files += [ entry ]
+
+print(f"  Found {len(files)} files")
+
+missing = [ ]
+read = 0
+skip = 0
+for f in files:
+    try:
+        keys = set(mutagen.File(f).keys())
+        if sys.argv[1] not in keys:
+            missing += [ f ]
+        read += 1
+    except Exception as e:
+        #print(e)
+        skip += 1
+
+print(f"  Read {read} files, skipped {skip}")
+
+print(f"  There are {len(missing)} files missing the \"{sys.argv[1]}\" tag:")
+for f in missing:
+    print(f"    {f}")
+print()