use UUID object for uuids instead of base64 string

README.rst

@@ -57,7 +57,7 @@ Finding Entries
 
 **find_entries** (title=None, username=None, password=None, url=None, notes=None, path=None, uuid=None, string=none, group=None, recursive=True, regex=False, flags=None, history=False, first=False)
 
-Returns entries which match all provided parameters, where ``title``, ``username``, ``password``, ``url``, ``notes``, ``path``, ``uuid`` and ``autotype_sequence`` are strings, ``string`` is a dict, ``autotype_enabled`` is a boolean.  This function has optional ``regex`` boolean and ``flags`` string arguments, which means to interpret search strings as `XSLT style`_ regular expressions with `flags`_.
+Returns entries which match all provided parameters, where ``title``, ``username``, ``password``, ``url``, ``notes``, ``path``, and ``autotype_sequence`` are strings, ``string`` is a dict, ``autotype_enabled`` is a boolean, ``uuid`` is a ``uuid.UUID``.  This function has optional ``regex`` boolean and ``flags`` string arguments, which means to interpret search strings as `XSLT style`_ regular expressions with `flags`_.
 
 .. _XSLT style: https://www.xml.com/pub/a/2003/06/04/tr.html
 .. _flags: https://www.w3.org/TR/xpath-functions/#flags 
@@ -106,7 +106,7 @@ Finding Groups
 
 **find_groups** (name=None, path=None, uuid=None, notes=None, group=None, recursive=True, regex=False, flags=None, first=False)
 
-where ``name``, ``path``, ``uuid`` and ``notes`` are strings.  This function has optional ``regex`` boolean and ``flags`` string arguments, which means to interpret search strings as `XSLT style`_ regular expressions with `flags`_.
+where ``name``, ``path``, and ``notes`` are strings, ``uuid`` is a ``uuid.UUID``. This function has optional ``regex`` boolean and ``flags`` string arguments, which means to interpret search strings as `XSLT style`_ regular expressions with `flags`_.
 
 .. _XSLT style: https://www.xml.com/pub/a/2003/06/04/tr.html
 .. _flags: https://www.w3.org/TR/xpath-functions/#flags 

pykeepass/baseelement.py

@@ -69,11 +69,15 @@ def dump_xml(self, pretty_print=False):
 
     @property
     def uuid(self):
-        return self._get_subelement_text('UUID')
+        """Returns uuid of this element as a uuid.UUID object"""
+        b64_uuid = self._get_subelement_text('UUID')
+        return uuid.UUID(bytes=base64.b64decode(b64_uuid))
 
     @uuid.setter
-    def uuid(self, value):
-        return self._set_subelement_text('UUID', value)
+    def uuid(self, uuid):
+        """Set element uuid. `uuid` is a uuid.UUID object"""
+        b64_uuid = base64.b64encode(uuid.bytes).decode('utf-8')
+        return self._set_subelement_text('UUID', b64_uuid)
 
     @property
     def icon(self):

pykeepass/pykeepass.py

@@ -204,6 +204,10 @@ def _find(self, prefix, keys_xp, path=None, tree=None, first=False,
 
                 kwargs.pop('string')
 
+            # convert uuid to base64 form before building xpath
+            if 'uuid' in kwargs.keys():
+                kwargs['uuid'] = base64.b64encode(kwargs['uuid'].bytes).decode('utf-8')
+
             # build xpath to filter results with specified attributes
             for key, value in kwargs.items():
                 if key not in keys_xp[regex].keys():

tests/tests.py

@@ -12,6 +12,7 @@
 from pykeepass.kdbx_parsing import KDBX
 from pykeepass.exceptions import BinaryError
 from lxml.etree import Element
+import uuid
 import os
 import shutil
 import unittest
@@ -98,16 +99,18 @@ def test_find_entries_by_path(self):
         self.assertEqual('group_entry', results.title)
 
     def test_find_entries_by_uuid(self):
-        results = self.kp.find_entries_by_uuid('zF9+zSoASMqWIcIio0ewuw==')[0]
+        uu = uuid.UUID('cc5f7ecd-2a00-48ca-9621-c222a347b0bb')
+        results = self.kp.find_entries_by_uuid(uu)[0]
         self.assertIsInstance(results, Entry)
-        self.assertEqual('zF9+zSoASMqWIcIio0ewuw==', results.uuid)
+        self.assertEqual(uu, results.uuid)
         self.assertEqual('foobar_user', results.username)
 
     def test_find_entries_by_string(self):
         results = self.kp.find_entries_by_string({'custom_field': 'custom field value'})[0]
         self.assertIsInstance(results, Entry)
         self.assertEqual('custom field value', results.get_custom_property('custom_field'))
-        self.assertEqual('HnN4bHSVjEybPf8nOq1bVA==', results.uuid)
+        uu = uuid.UUID('1e73786c-7495-8c4c-9b3d-ff273aad5b54')
+        self.assertEqual(uu, results.uuid)
 
     def test_find_entries_by_autotype_sequence(self):
         results = self.kp.find_entries(autotype_sequence='{TAB}', regex=True)
@@ -272,15 +275,17 @@ def test_find_groups_by_path(self):
         self.assertEqual(results, None)
 
     def test_find_groups_by_uuid(self):
-        results = self.kp.find_groups_by_uuid('lRVaMlMXoQ/U5NDCAwJktg==', first=True)
+        uu = uuid.UUID('95155a32-5317-a10f-d4e4-d0c2030264b6')
+        results = self.kp.find_groups_by_uuid(uu, first=True)
         self.assertIsInstance(results, Group)
-        results = self.kp.find_groups(uuid='^lRVaMlMX|^kwTZdSoU', regex=True)
-        self.assertEqual(len(results), 2)
+        results = self.kp.find_groups(uuid=uu, regex=True)
+        self.assertEqual(len(results), 1)
 
     def test_find_groups_by_notes(self):
         results = self.kp.find_groups(notes='group notes')
         self.assertEqual(len(results), 1)
-        self.assertEqual(results[0].uuid, 'lRVaMlMXoQ/U5NDCAwJktg==')
+        uu = uuid.UUID('95155a32-5317-a10f-d4e4-d0c2030264b6')
+        self.assertEqual(results[0].uuid, uu)
 
     def test_groups(self):
         results = self.kp.groups