MDP-448 Make ms_to_datetime always return a non-naive datetime.datetime

Author: jamesblackburn

arctic/date/_util.py

@@ -134,8 +134,8 @@ def ms_to_datetime(ms, tzinfo=None):
     if not isinstance(ms, (int, long)):
         raise TypeError('expected integer, not %s' % type(ms))
 
-    if tzinfo in (None, mktz()):
-        return datetime.datetime.fromtimestamp(ms * 1e-3, mktz()).replace(tzinfo=None)
+    if tzinfo is None:
+        tzinfo = mktz()
 
     return datetime.datetime.fromtimestamp(ms * 1e-3, tzinfo)
 

arctic/store/version_store.py

@@ -237,7 +237,7 @@ def list_versions(self, symbol=None, snapshot=None, latest_only=False):
                     continue
                 seen_symbols.add(version['symbol'])
                 versions.append({'symbol': version['symbol'], 'version': version['version'],
-                       # We return naive datetimes in London Time.
+                       # We return naive datetimes in Local Time.
                        'date': ms_to_datetime(datetime_to_ms(version['_id'].generation_time)),
                        'snapshots': self._find_snapshots(version.get('parent', []))})
         return versions

tests/unit/date/test_datetime_to_ms_roundtrip.py

@@ -11,7 +11,6 @@ def assert_roundtrip(tz):
 
     ts1 = ts.replace(tzinfo=tz)
     ts2 = ms_to_datetime(datetime_to_ms(ts1.astimezone(mktz("UTC"))), tz)
-    ts1 = ts1.replace(tzinfo=None) if tz == mktz() else ts1
     #logger.info(ts2.tzinfo)
 
     assert(ts2.hour == ts1.hour)
@@ -53,22 +52,22 @@ def test_mktz_London():
 
 def test_datetime_roundtrip_local_no_tz():
     pdt = datetime.datetime(2012, 6, 12, 12, 12, 12, 123000)
-    pdt2 = ms_to_datetime(datetime_to_ms(pdt))
+    pdt2 = ms_to_datetime(datetime_to_ms(pdt)).replace(tzinfo=None)
     assert pdt2 == pdt
 
     pdt = datetime.datetime(2012, 1, 12, 12, 12, 12, 123000)
-    pdt2 = ms_to_datetime(datetime_to_ms(pdt))
+    pdt2 = ms_to_datetime(datetime_to_ms(pdt)).replace(tzinfo=None)
     assert pdt2 == pdt
 
 
 def test_datetime_roundtrip_local_tz():
     pdt = datetime.datetime(2012, 6, 12, 12, 12, 12, 123000, tzinfo=mktz(DEFAULT_TIME_ZONE_NAME))
     pdt2 = ms_to_datetime(datetime_to_ms(pdt))
-    assert pdt2 == pdt.replace(tzinfo=None)
+    assert pdt2 == pdt
 
     pdt = datetime.datetime(2012, 1, 12, 12, 12, 12, 123000, tzinfo=mktz(DEFAULT_TIME_ZONE_NAME))
     pdt2 = ms_to_datetime(datetime_to_ms(pdt))
-    assert pdt2 == pdt.replace(tzinfo=None)
+    assert pdt2 == pdt
 
 
 def test_datetime_roundtrip_est_tz():

tests/unit/date/test_util.py

@@ -18,15 +18,13 @@
 def test_datetime_to_ms_and_back(pdt):
     i = datetime_to_ms(pdt)
     pdt = pdt.astimezone(mktz())
-    pdt = pdt.replace(tzinfo=None)
     pdt2 = ms_to_datetime(i)
     assert pdt == pdt2
 
 
 def test_datetime_to_ms_and_back_microseconds():
     pdt = dt(2012, 8, 1, 12, 34, 56, 999999, tzinfo=mktz(DEFAULT_TIME_ZONE_NAME))
     i = datetime_to_ms(pdt)
-    pdt = pdt.replace(tzinfo=None)
     pdt2 = ms_to_datetime(i)
 
     assert pdt != pdt2
@@ -38,7 +36,6 @@ def test_datetime_to_ms_and_back_microseconds():
     assert pdt.second == pdt2.second
     #   Microsecond precision loss inevitable.
     assert pdt.microsecond // 1000 == pdt2.microsecond // 1000
-    assert pdt.tzinfo is None
 
 
 def test_daterange_closedclosed_None():