Database parental directories creation if not exist

beets/ui/__init__.py

@@ -1207,10 +1207,22 @@ def _configure(options):
     return config
 
 
+def _ensure_db_directory_exists(path):
+    if path == b':memory:':  # in memory db
+        return
+    newpath = os.path.dirname(path)
+    if not os.path.isdir(newpath):
+        if input_yn("The database directory {} does not \
+                       exist. Create it (Y/n)?"
+                    .format(util.displayable_path(newpath))):
+            os.makedirs(newpath)
+
+
 def _open_library(config):
     """Create a new library instance from the configuration.
     """
     dbpath = util.bytestring_path(config['library'].as_filename())
+    _ensure_db_directory_exists(dbpath)
     try:
         lib = library.Library(
             dbpath,

docs/changelog.rst

@@ -8,6 +8,8 @@ Changelog goes here!
 
 New features:
 
+* Create the parental directories for database if they do not exist.
+  :bug:`3808` :bug:`4327`
 * :ref:`musicbrainz-config`: a new :ref:`musicbrainz.enabled` option allows disabling 
   the MusicBrainz metadata source during the autotagging process
 * :doc:`/plugins/kodiupdate`: Now supports multiple kodi instances

test/test_dbcore.py

@@ -763,5 +763,6 @@ def test_no_results(self):
 def suite():
     return unittest.TestLoader().loadTestsFromName(__name__)
 
+
 if __name__ == '__main__':
     unittest.main(defaultTest='suite')

test/test_ui_init.py

@@ -15,11 +15,16 @@
 """Test module for file ui/__init__.py
 """
 
-
+import os
+import shutil
 import unittest
-from test import _common
+from random import random
+from copy import deepcopy
 
 from beets import ui
+from test import _common
+from test.helper import control_stdin
+from beets import config
 
 
 class InputMethodsTest(_common.TestCase):
@@ -121,8 +126,39 @@ def test_human_seconds(self):
             self.assertEqual(h, ui.human_seconds(i))
 
 
+class ParentalDirCreation(_common.TestCase):
+    def test_create_yes(self):
+        non_exist_path = _common.util.py3_path(os.path.join(
+            self.temp_dir, b'nonexist', str(random()).encode()))
+        # Deepcopy instead of recovering because exceptions might
+        # occcur; wish I can use a golang defer here.
+        test_config = deepcopy(config)
+        test_config['library'] = non_exist_path
+        with control_stdin('y'):
+            ui._open_library(test_config)
+
+    def test_create_no(self):
+        non_exist_path_parent = _common.util.py3_path(
+            os.path.join(self.temp_dir, b'nonexist'))
+        non_exist_path = _common.util.py3_path(os.path.join(
+            non_exist_path_parent.encode(), str(random()).encode()))
+        test_config = deepcopy(config)
+        test_config['library'] = non_exist_path
+
+        with control_stdin('n'):
+            try:
+                ui._open_library(test_config)
+            except ui.UserError:
+                if os.path.exists(non_exist_path_parent):
+                    shutil.rmtree(non_exist_path_parent)
+                    raise OSError("Parent directories should not be created.")
+            else:
+                raise OSError("Parent directories should not be created.")
+
+
 def suite():
     return unittest.TestLoader().loadTestsFromName(__name__)
 
+
 if __name__ == '__main__':
     unittest.main(defaultTest='suite')