adjust date_range tests for D

Author: Matt Roeschke

doc/source/whatsnew/v0.24.0.txt

@@ -319,7 +319,7 @@ that the dates have been converted to UTC
 
 :class:`Day` and associated frequency alias ``'D'`` were documented to represent
 a calendar day; however, arithmetic and operations with :class:`Day` sometimes
-respected absolute time (i.e. ```Day(n)`` and acted identically to ```Timedelta(days=n)``).
+respected absolute time instead (i.e. ```Day(n)`` and acted identically to ```Timedelta(days=n)``).
 
 *Previous Behavior*:
 

pandas/core/arrays/datetimes.py

@@ -241,11 +241,11 @@ def _generate_range(cls, start, end, periods, freq, tz=None,
 
         tz, _ = _infer_tz_from_endpoints(start, end, tz)
 
-        # If we have a Timedelta-like frequency (Tick) make sure tz
-        # is set before generating the range. For relative frequencies,
-        # generate the range with naive dates.
+        # Make sure start and end are timezone localized if:
+        # 1) freq = a Timedelta-like frequency (Tick)
+        # 2) freq = None i.e. generating a linspaced range
         localize_args = {'tz': None}
-        if isinstance(freq, Tick):
+        if isinstance(freq, Tick) or freq is None:
             localize_args = {'tz': tz, 'ambiguous': False}
         if tz is not None:
             # Localize the start and end arguments
@@ -287,8 +287,6 @@ def _generate_range(cls, start, end, periods, freq, tz=None,
                     end = end.tz_localize(tz).asm8
         else:
             # Create a linearly spaced date_range in local time
-            start = start.tz_localize(tz)
-            end = end.tz_localize(tz)
             arr = np.linspace(start.value, end.value, periods)
             index = cls._simple_new(arr.astype('M8[ns]'), freq=None, tz=tz)
 

pandas/tests/indexes/datetimes/test_date_range.py

@@ -336,28 +336,28 @@ def test_range_tz_pytz(self):
         assert dr[0] == start
         assert dr[2] == end
 
-    def test_range_tz_dst_straddle_pytz(self):
-        tz = timezone('US/Eastern')
-        dates = [(tz.localize(datetime(2014, 3, 6)),
-                  tz.localize(datetime(2014, 3, 12))),
-                 (tz.localize(datetime(2013, 11, 1)),
-                  tz.localize(datetime(2013, 11, 6)))]
-        for (start, end) in dates:
-            dr = date_range(start, end, freq='D')
-            assert dr[0] == start
-            assert dr[-1] == end
-            assert np.all(dr.hour == 0)
-
-            dr = date_range(start, end, freq='D', tz='US/Eastern')
-            assert dr[0] == start
-            assert dr[-1] == end
-            assert np.all(dr.hour == 0)
-
-            dr = date_range(start.replace(tzinfo=None), end.replace(
-                tzinfo=None), freq='D', tz='US/Eastern')
-            assert dr[0] == start
-            assert dr[-1] == end
-            assert np.all(dr.hour == 0)
+    @pytest.mark.parametrize('start, end', [
+        [Timestamp(datetime(2014, 3, 6), tz='US/Eastern'),
+         Timestamp(datetime(2014, 3, 12), tz='US/Eastern')],
+        [Timestamp(datetime(2013, 11, 1), tz='US/Eastern'),
+         Timestamp(datetime(2013, 11, 6), tz='US/Eastern')]
+    ])
+    def test_range_tz_dst_straddle_pytz(self, start, end):
+        dr = date_range(start, end, freq='CD')
+        assert dr[0] == start
+        assert dr[-1] == end
+        assert np.all(dr.hour == 0)
+
+        dr = date_range(start, end, freq='CD', tz='US/Eastern')
+        assert dr[0] == start
+        assert dr[-1] == end
+        assert np.all(dr.hour == 0)
+
+        dr = date_range(start.replace(tzinfo=None), end.replace(
+            tzinfo=None), freq='CD', tz='US/Eastern')
+        assert dr[0] == start
+        assert dr[-1] == end
+        assert np.all(dr.hour == 0)
 
     def test_range_tz_dateutil(self):
         # see gh-2906

pandas/tests/indexes/datetimes/test_timezones.py

@@ -429,24 +429,24 @@ def test_dti_tz_localize_utc_conversion(self, tz):
         with pytest.raises(pytz.NonExistentTimeError):
             rng.tz_localize(tz)
 
-    def test_dti_tz_localize_roundtrip(self, tz_aware_fixture):
+    @pytest.mark.parametrize('idx', [
+        date_range(start='2014-01-01', end='2014-12-31', freq='M'),
+        date_range(start='2014-01-01', end='2014-12-31', freq='CD'),
+        date_range(start='2014-01-01', end='2014-03-01', freq='H'),
+        date_range(start='2014-08-01', end='2014-10-31', freq='T')
+    ])
+    def test_dti_tz_localize_roundtrip(self, tz_aware_fixture, idx):
         tz = tz_aware_fixture
+        localized = idx.tz_localize(tz)
+        expected = date_range(start=idx[0], end=idx[-1], freq=idx.freq,
+                              tz=tz)
+        tm.assert_index_equal(localized, expected)
+        with pytest.raises(TypeError):
+            localized.tz_localize(tz)
 
-        idx1 = date_range(start='2014-01-01', end='2014-12-31', freq='M')
-        idx2 = date_range(start='2014-01-01', end='2014-12-31', freq='D')
-        idx3 = date_range(start='2014-01-01', end='2014-03-01', freq='H')
-        idx4 = date_range(start='2014-08-01', end='2014-10-31', freq='T')
-        for idx in [idx1, idx2, idx3, idx4]:
-            localized = idx.tz_localize(tz)
-            expected = date_range(start=idx[0], end=idx[-1], freq=idx.freq,
-                                  tz=tz)
-            tm.assert_index_equal(localized, expected)
-            with pytest.raises(TypeError):
-                localized.tz_localize(tz)
-
-            reset = localized.tz_localize(None)
-            tm.assert_index_equal(reset, idx)
-            assert reset.tzinfo is None
+        reset = localized.tz_localize(None)
+        tm.assert_index_equal(reset, idx)
+        assert reset.tzinfo is None
 
     def test_dti_tz_localize_naive(self):
         rng = date_range('1/1/2011', periods=100, freq='H')
@@ -1033,7 +1033,9 @@ def test_date_range_span_dst_transition(self, tzstr):
         assert (dr.hour == 0).all()
 
         dr = date_range('2012-11-02', periods=10, tz=tzstr)
-        assert (dr.hour == 0).all()
+        result = dr.hour
+        expected = Index([0, 0, 0, 23, 23, 23, 23, 23, 23, 23])
+        tm.assert_index_equal(result, expected)
 
     @pytest.mark.parametrize('tzstr', ['US/Eastern', 'dateutil/US/Eastern'])
     def test_date_range_timezone_str_argument(self, tzstr):

pandas/tseries/offsets.py

@@ -2348,7 +2348,7 @@ class Nano(Tick):
 
 
 def generate_range(start=None, end=None, periods=None,
-                   offset=BDay()):
+                   offset=BDay(), time_rule=None):
     """
     Generates a sequence of dates corresponding to the specified time
     offset. Similar to dateutil.rrule except uses pandas DateOffset
@@ -2360,6 +2360,8 @@ def generate_range(start=None, end=None, periods=None,
     end : datetime (default None)
     periods : int, (default None)
     offset : DateOffset, (default BDay())
+    time_rule : (legacy) name of DateOffset object to be used, optional
+        Corresponds with names expected by tseries.frequencies.get_offset
 
     Notes
     -----
@@ -2372,6 +2374,10 @@ def generate_range(start=None, end=None, periods=None,
     -------
     dates : generator object
     """
+    if time_rule is not None:
+        from pandas.tseries.frequencies import get_offset
+
+        offset = get_offset(time_rule)
 
     start = to_datetime(start)
     end = to_datetime(end)