BUG: initialize DatetimeIndex with array of strings (#4229)

Author: jorisvandenbossche

doc/source/release.rst

@@ -338,6 +338,8 @@ pandas 0.12
   - Fixed the legend displaying in ``DataFrame.plot(kind='kde')`` (:issue:`4216`)
   - Fixed bug where Index slices weren't carrying the name attribute
     (:issue:`4226`)
+  - Fixed bug in initializing ``DatetimeIndex`` with an array of strings
+    in a certain time zone (:issue:`4229`)
 
 pandas 0.11.0
 =============

doc/source/v0.12.0.txt

@@ -471,7 +471,9 @@ Bug Fixes
   - Fixed the legend displaying in ``DataFrame.plot(kind='kde')`` (:issue:`4216`)
   - Fixed bug where Index slices weren't carrying the name attribute
     (:issue:`4226`)
-    
+  - Fixed bug in initializing ``DatetimeIndex`` with an array of strings
+    in a certain time zone (:issue:`4229`)
+
 See the :ref:`full release notes
 <release>` or issue tracker
 on GitHub for a complete list.

pandas/tseries/index.py

@@ -208,9 +208,10 @@ def __new__(cls, data=None,
                     return data
 
         if issubclass(data.dtype.type, basestring):
-            subarr = _str_to_dt_array(data, offset, dayfirst=dayfirst,
+            data = _str_to_dt_array(data, offset, dayfirst=dayfirst,
                                       yearfirst=yearfirst)
-        elif issubclass(data.dtype.type, np.datetime64):
+
+        if issubclass(data.dtype.type, np.datetime64):
             if isinstance(data, DatetimeIndex):
                 if tz is None:
                     tz = data.tz

pandas/tseries/tests/test_timezones.py

@@ -631,6 +631,22 @@ def test_index_drop_dont_lose_tz(self):
 
         self.assertTrue(ind.tz is not None)
 
+    def test_datetimeindex_tz(self):
+        """ Test different DatetimeIndex constructions with timezone
+        Follow-up of #4229
+        """
+        
+        arr = ['11/10/2005 08:00:00', '11/10/2005 09:00:00']
+        
+        idx1 = to_datetime(arr).tz_localize('US/Eastern')
+        idx2 = DatetimeIndex(start="2005-11-10 08:00:00", freq='H', periods=2, tz='US/Eastern')
+        idx3 = DatetimeIndex(arr, tz='US/Eastern')
+        idx4 = DatetimeIndex(np.array(arr), tz='US/Eastern')
+        
+        for other in [idx2, idx3, idx4]:
+            self.assert_(idx1.equals(other))
+
+
 class TestTimeZones(unittest.TestCase):
     _multiprocess_can_split_ = True