Use plyvel for the leveldb backend

Rationales:
- quickumls fails to install on Python 3.12 due to py-leveldb
- py-leveldb looks unmaintained and is unlikely to receive support for Python 3.12
- plyvel provides a suitable replacement and is compatible with Python 3.12 onwards

Closes Georgetown-IR-Lab#98

quickumls/toolbox.py

@@ -12,7 +12,7 @@
 
 # installed modules
 import numpy
-import leveldb
+import plyvel
 try:
     import unqlite
     UNQLITE_AVAILABLE = True
@@ -240,12 +240,12 @@ def __init__(self, path, database_backend='leveldb'):
             self.semtypes_db_put = self.semtypes_db.store
             self.semtypes_db_get = self.semtypes_db.fetch
         elif database_backend == 'leveldb':
-            self.cui_db = leveldb.LevelDB(os.path.join(path, 'cui.leveldb'))
-            self.cui_db_put = self.cui_db.Put
-            self.cui_db_get = self.cui_db.Get
-            self.semtypes_db = leveldb.LevelDB(os.path.join(path, 'semtypes.leveldb'))
-            self.semtypes_db_put = self.semtypes_db.Put
-            self.semtypes_db_get = self.semtypes_db.Get
+            self.cui_db = plyvel.DB(os.path.join(path, 'cui.leveldb'))
+            self.cui_db_put = self.cui_db.put
+            self.cui_db_get = self.cui_db.get
+            self.semtypes_db = plyvel.DB(os.path.join(path, 'semtypes.leveldb'))
+            self.semtypes_db_put = self.semtypes_db.put
+            self.semtypes_db_get = self.semtypes_db.get
         else:
             raise ValueError(f'database_backend {database_backend} not recognized')
 

requirements.txt

@@ -1,4 +1,4 @@
-leveldb>=0.193
+plyvel>=1.5.1
 numpy>=1.8.2
 spacy>=3.0.6
 unidecode>=0.4.19