Fix issue pandas-dev#15683

Adjustments to coding guidelines

Only perform timestamp() check if meth is available.

Added sv

Author: Stefan Scherfke

asv_bench/benchmarks/timestamp.py

@@ -0,0 +1,17 @@
+import pytz
+import pandas as pd
+import datetime
+
+
+class TimeTimestamp(object):
+
+    goal_time = 0.5
+
+    def setup(self):
+        self.ts = pd.Timestamp("2016-03-28")  # after DST
+        self.tzinfo = pytz.timezone("CET")
+
+    def time_replace(self):
+        self.ts.replace(tzinfo=self.tzinfo).replace(tzinfo=None)
+
+

doc/source/whatsnew/v0.20.0.txt

@@ -21,6 +21,7 @@ Highlights include:
 - Window binary corr/cov operations now return a MultiIndexed ``DataFrame`` rather than a ``Panel``, as ``Panel`` is now deprecated, see :ref:`here <whatsnew_0200.api_breaking.rolling_pairwise>`
 - Support for S3 handling now uses ``s3fs``, see :ref:`here <whatsnew_0200.api_breaking.s3>`
 - Google BigQuery support now uses the ``pandas-gbq`` library, see :ref:`here <whatsnew_0200.api_breaking.gbq>`
+- Switched the test framework to use `pytest <http://doc.pytest.org/en/latest>`__ (:issue:`13097`)
 
 .. warning::
 
@@ -1568,7 +1569,12 @@ Conversion
 
 - Bug in ``Timestamp.replace`` now raises ``TypeError`` when incorrect argument names are given; previously this raised ``ValueError`` (:issue:`15240`)
 - Bug in ``Timestamp.replace`` with compat for passing long integers (:issue:`15030`)
+<<<<<<< HEAD
 - Bug in ``Timestamp`` returning UTC based time/date attributes when a timezone was provided (:issue:`13303`, :issue:`6538`)
+=======
+- Bug in ``Timestamp.replace`` when replacing ``tzinfo`` around DST changes (:issue:`15683`)
+- Bug in ``Timestamp`` returning UTC based time/date attributes when a timezone was provided (:issue:`13303`)
+>>>>>>> Adjustments to coding guidelines
 - Bug in ``Timestamp`` incorrectly localizing timezones during construction (:issue:`11481`, :issue:`15777`)
 - Bug in ``TimedeltaIndex`` addition where overflow was being allowed without error (:issue:`14816`)
 - Bug in ``TimedeltaIndex`` raising a ``ValueError`` when boolean indexing with ``loc`` (:issue:`14946`)

pandas/_libs/tslib.pyx

@@ -685,14 +685,16 @@ class Timestamp(_Timestamp):
         cdef:
             pandas_datetimestruct dts
             int64_t value
-            object _tzinfo, result, k, v
+            object _tzinfo, result, k, v, ts_input
             _TSObject ts
 
         # set to naive if needed
         _tzinfo = self.tzinfo
         value = self.value
         if _tzinfo is not None:
-            value = tz_convert_single(value, 'UTC', _tzinfo)
+            value_tz = tz_convert_single(value, _tzinfo, 'UTC')
+            offset = value - value_tz
+            value += offset
 
         # setup components
         pandas_datetime_to_datetimestruct(value, PANDAS_FR_ns, &dts)
@@ -726,16 +728,14 @@ class Timestamp(_Timestamp):
             _tzinfo = tzinfo
 
         # reconstruct & check bounds
-        value = pandas_datetimestruct_to_datetime(PANDAS_FR_ns, &dts)
+        ts_input = datetime(dts.year, dts.month, dts.day, dts.hour, dts.min,
+                            dts.sec, dts.us, tzinfo=_tzinfo)
+        ts = convert_to_tsobject(ts_input, _tzinfo, None, 0, 0)
+        value = ts.value + (dts.ps // 1000)
         if value != NPY_NAT:
             _check_dts_bounds(&dts)
 
-        # set tz if needed
-        if _tzinfo is not None:
-            value = tz_convert_single(value, _tzinfo, 'UTC')
-
-        result = create_timestamp_from_ts(value, dts, _tzinfo, self.freq)
-        return result
+        return create_timestamp_from_ts(value, dts, _tzinfo, self.freq)
 
     def isoformat(self, sep='T'):
         base = super(_Timestamp, self).isoformat(sep=sep)

pandas/tests/tseries/test_timezones.py

@@ -1256,6 +1256,27 @@ def test_ambiguous_compat(self):
             assert (result_pytz.to_pydatetime().tzname() ==
                     result_dateutil.to_pydatetime().tzname())
 
+    def test_replace_tzinfo(self):
+        # GH 15683
+        dt = datetime(2016, 3, 27, 1)
+        tzinfo = pytz.timezone('CET').localize(dt, is_dst=False).tzinfo
+
+        result_dt = dt.replace(tzinfo=tzinfo)
+        result_pd = Timestamp(dt).replace(tzinfo=tzinfo)
+
+        if hasattr(result_dt, 'timestamp'):  # New method in Py 3.3
+            assert result_dt.timestamp() == result_pd.timestamp()
+        assert result_dt == result_pd
+        assert result_dt == result_pd.to_pydatetime()
+
+        result_dt = dt.replace(tzinfo=tzinfo).replace(tzinfo=None)
+        result_pd = Timestamp(dt).replace(tzinfo=tzinfo).replace(tzinfo=None)
+
+        if hasattr(result_dt, 'timestamp'):  # New method in Py 3.3
+            assert result_dt.timestamp() == result_pd.timestamp()
+        assert result_dt == result_pd
+        assert result_dt == result_pd.to_pydatetime()
+
     def test_index_equals_with_tz(self):
         left = date_range('1/1/2011', periods=100, freq='H', tz='utc')
         right = date_range('1/1/2011', periods=100, freq='H', tz='US/Eastern')