Replace datetime.utcfromtimestamp

Only method available out-of-box for this purpose is `datetime.fromtimestamp`.
But it either include timezone into datetime which is not acceptable (because datetime` implementation does not allow you to compare `datetime` with `tz_info` and wihtout it)
  or offset `datetime` from utc which we don't want to happen because it changes actual time.
On other hand `tz_info` in not writable on `datetime` and all API that allows you to manipulate it offsets time as well.
So, simpliest solution would to be ship a function that calls `datetime.fromtimestamp` and then builds exactly same `datetime` with `tz_info` empty.

Author: dkropachev

cassandra/cqlengine/columns.py

@@ -21,7 +21,7 @@
 from cassandra.cqltypes import SimpleDateType, _cqltypes, UserType
 from cassandra.cqlengine import ValidationError
 from cassandra.cqlengine.functions import get_total_seconds
-from cassandra.util import Duration as _Duration
+from cassandra.util import Duration as _Duration, utcfromtimestamp
 
 log = logging.getLogger(__name__)
 
@@ -551,7 +551,7 @@ def to_python(self, value):
         elif isinstance(value, date):
             return datetime(*(value.timetuple()[:6]))
 
-        return datetime.utcfromtimestamp(value)
+        return utcfromtimestamp(value)
 
     def to_database(self, value):
         value = super(DateTime, self).to_database(value)

cassandra/util.py

@@ -40,8 +40,17 @@
 
 from cassandra import DriverException
 
+
+def utcfromtimestamp(timestamp):
+    """
+    It replicates behavior of datetime.utcfromtimestamp
+    """
+    dt = datetime.datetime.fromtimestamp(timestamp, datetime.timezone.utc)
+    return datetime.datetime(dt.year, dt.month, dt.day, dt.hour, dt.minute, dt.second, dt.microsecond, fold=dt.fold)
+
+
 DATETIME_EPOC = datetime.datetime(1970, 1, 1)
-UTC_DATETIME_EPOC = datetime.datetime.utcfromtimestamp(0)
+UTC_DATETIME_EPOC = utcfromtimestamp(0)
 
 _nan = float('nan')
 

tests/integration/cqlengine/columns/test_validation.py

@@ -15,7 +15,7 @@
 import unittest
 
 import sys
-from datetime import datetime, timedelta, date, tzinfo, time
+from datetime import datetime, timedelta, date, tzinfo, time, timezone
 from decimal import Decimal as D
 from uuid import uuid4, uuid1
 from packaging.version import Version
@@ -30,6 +30,7 @@
 from cassandra.cqlengine.models import Model, ValidationError
 from cassandra.cqlengine.usertype import UserType
 from cassandra import util
+from cassandra.util import utcfromtimestamp
 
 from tests.integration import PROTOCOL_VERSION, CASSANDRA_VERSION, greaterthanorequalcass30, greaterthanorequalcass3_11
 from tests.integration.cqlengine.base import BaseCassEngTestCase
@@ -97,7 +98,7 @@ def test_datetime_timestamp(self):
         dt_value = 1454520554
         self.DatetimeTest.objects.create(test_id=5, created_at=dt_value)
         dt2 = self.DatetimeTest.objects(test_id=5).first()
-        self.assertEqual(dt2.created_at, datetime.utcfromtimestamp(dt_value))
+        self.assertEqual(dt2.created_at, utcfromtimestamp(dt_value))
 
     def test_datetime_large(self):
         dt_value = datetime(2038, 12, 31, 10, 10, 10, 123000)
@@ -809,7 +810,7 @@ def test_conversion_specific_date(self):
         assert isinstance(uuid, UUID)
 
         ts = (uuid.time - 0x01b21dd213814000) / 1e7 # back to a timestamp
-        new_dt = datetime.utcfromtimestamp(ts)
+        new_dt = utcfromtimestamp(ts)
 
         # checks that we created a UUID1 with the proper timestamp
         assert new_dt == dt

tests/integration/cqlengine/model/test_model_io.py

@@ -15,7 +15,7 @@
 
 from uuid import uuid4, UUID
 import random
-from datetime import datetime, date, time
+from datetime import datetime, date, time, timezone
 from decimal import Decimal
 from operator import itemgetter
 
@@ -26,7 +26,7 @@
 from cassandra.cqlengine.management import drop_table
 from cassandra.cqlengine.models import Model
 from cassandra.query import SimpleStatement
-from cassandra.util import Date, Time, Duration
+from cassandra.util import Date, Time, Duration, utcfromtimestamp
 from cassandra.cqlengine.statements import SelectStatement, DeleteStatement, WhereClause
 from cassandra.cqlengine.operators import EqualsOperator
 
@@ -200,13 +200,13 @@ class AllDatatypesModel(Model):
 
         sync_table(AllDatatypesModel)
 
-        input = ['ascii', 2 ** 63 - 1, bytearray(b'hello world'), True, datetime.utcfromtimestamp(872835240),
+        input = ['ascii', 2 ** 63 - 1, bytearray(b'hello world'), True, utcfromtimestamp(872835240),
                  Decimal('12.3E+7'), 2.39, 3.4028234663852886e+38, '123.123.123.123', 2147483647, 'text',
                  UUID('FE2B4360-28C6-11E2-81C1-0800200C9A66'), UUID('067e6162-3b6f-4ae2-a171-2470b63dff00'),
                  int(str(2147483647) + '000')]
 
         AllDatatypesModel.create(id=0, a='ascii', b=2 ** 63 - 1, c=bytearray(b'hello world'), d=True,
-                                 e=datetime.utcfromtimestamp(872835240), f=Decimal('12.3E+7'), g=2.39,
+                                 e=utcfromtimestamp(872835240), f=Decimal('12.3E+7'), g=2.39,
                                  h=3.4028234663852886e+38, i='123.123.123.123', j=2147483647, k='text',
                                  l=UUID('FE2B4360-28C6-11E2-81C1-0800200C9A66'),
                                  m=UUID('067e6162-3b6f-4ae2-a171-2470b63dff00'), n=int(str(2147483647) + '000'),

tests/integration/cqlengine/model/test_udts.py

@@ -13,7 +13,7 @@
 # limitations under the License.
 import unittest
 
-from datetime import datetime, date, time
+from datetime import datetime, date, time, timezone
 from decimal import Decimal
 from mock import Mock
 from uuid import UUID, uuid4
@@ -23,7 +23,7 @@
 from cassandra.cqlengine import columns, connection
 from cassandra.cqlengine.management import sync_table, drop_table, sync_type, create_keyspace_simple, drop_keyspace
 from cassandra.cqlengine import ValidationError
-from cassandra.util import Date, Time
+from cassandra.util import Date, Time, utcfromtimestamp
 
 from tests.integration import PROTOCOL_VERSION
 from tests.integration.cqlengine.base import BaseCassEngTestCase
@@ -272,7 +272,7 @@ def test_can_insert_udts_with_all_datatypes(self):
         self.addCleanup(drop_table, AllDatatypesModel)
 
         input = AllDatatypes(a='ascii', b=2 ** 63 - 1, c=bytearray(b'hello world'), d=True,
-                             e=datetime.utcfromtimestamp(872835240), f=Decimal('12.3E+7'), g=2.39,
+                             e=utcfromtimestamp(872835240), f=Decimal('12.3E+7'), g=2.39,
                              h=3.4028234663852886e+38, i='123.123.123.123', j=2147483647, k='text',
                              l=UUID('FE2B4360-28C6-11E2-81C1-0800200C9A66'),
                              m=UUID('067e6162-3b6f-4ae2-a171-2470b63dff00'), n=int(str(2147483647) + '000'))

tests/unit/test_types.py

@@ -41,7 +41,7 @@
 from cassandra.util import (
     OPEN_BOUND, Date, DateRange, DateRangeBound,
     DateRangePrecision, Time, ms_timestamp_from_datetime,
-    datetime_from_timestamp
+    datetime_from_timestamp, utcfromtimestamp
 )
 from tests.unit.util import check_sequence_consistency
 
@@ -200,7 +200,7 @@ def test_empty_value(self):
 
     def test_datetype(self):
         now_time_seconds = time.time()
-        now_datetime = datetime.datetime.utcfromtimestamp(now_time_seconds)
+        now_datetime = utcfromtimestamp(now_time_seconds)
 
         # Cassandra timestamps in millis
         now_timestamp = now_time_seconds * 1e3
@@ -211,7 +211,7 @@ def test_datetype(self):
         # deserialize
         # epoc
         expected = 0
-        self.assertEqual(DateType.deserialize(int64_pack(1000 * expected), 0), datetime.datetime.utcfromtimestamp(expected))
+        self.assertEqual(DateType.deserialize(int64_pack(1000 * expected), 0), utcfromtimestamp(expected))
 
         # beyond 32b
         expected = 2 ** 33