QueryBuilder: add support for datetime.date objects in filters

aiida/common/hashing.py

@@ -8,6 +8,7 @@
 # For further information please visit http://www.aiida.net               #
 ###########################################################################
 """Common password and hash generation functions."""
+import datetime
 import hashlib
 try:  # Python > 3.5
     from hashlib import blake2b
@@ -18,7 +19,6 @@
 import time
 import uuid
 from collections import abc, OrderedDict
-from datetime import datetime
 from functools import singledispatch
 from itertools import chain
 from operator import itemgetter
@@ -234,17 +234,23 @@ def _(val, **kwargs):
     return [_single_digest('none')]
 
 
-@_make_hash.register(datetime)
+@_make_hash.register(datetime.datetime)
 def _(val, **kwargs):
     """hashes the little-endian rep of the float <epoch-seconds>.<subseconds>"""
     # see also https://stackoverflow.com/a/8778548 for an excellent elaboration
     if val.tzinfo is None or val.utcoffset() is None:
         val = val.replace(tzinfo=pytz.utc)
-    timestamp = val.timestamp()
 
+    timestamp = val.timestamp()
     return [_single_digest('datetime', float_to_text(timestamp, sig=AIIDA_FLOAT_PRECISION).encode('utf-8'))]
 
 
+@_make_hash.register(datetime.date)
+def _(val, **kwargs):
+    """Hashes the string representation in ISO format of the `datetime.date` object."""
+    return [_single_digest('date', val.isoformat().encode('utf-8'))]
+
+
 @_make_hash.register(uuid.UUID)
 def _(val, **kwargs):
     return [_single_digest('uuid', val.bytes)]

tests/orm/test_querybuilder.py

@@ -24,6 +24,16 @@ def setUp(self):
         self.clean_db()
         self.insert_data()
 
+    def test_date_filters_support(self):
+        """Verify that `datetime.date` is supported in filters."""
+        from datetime import datetime, date, timedelta
+
+        orm.Data(ctime=datetime.now() - timedelta(days=3)).store()
+        orm.Data(ctime=datetime.now() - timedelta(days=1)).store()
+
+        builder = orm.QueryBuilder().append(orm.Node, filters={'ctime': {'>': date.today() - timedelta(days=1)}})
+        self.assertEqual(builder.count(), 1)
+
     def test_ormclass_type_classification(self):
         """
         This tests the classifications of the QueryBuilder