BUG: add same to_timestamp change to PeriodIndex

Author: changhiskhan

pandas/tseries/period.py

@@ -773,12 +773,14 @@ def to_timestamp(self, freq=None, how='start'):
         -------
         DatetimeIndex
         """
+        how = _validate_end_alias(how)
+
         if freq is None:
             base, mult = _gfc(self.freq)
-            new_data = self
-        else:
-            base, mult = _gfc(freq)
-            new_data = self.asfreq(freq, how)
+            freq = _freq_mod.get_to_timestamp_base(base)
+
+        base, mult = _gfc(freq)
+        new_data = self.asfreq(freq, how)
 
         new_data = plib.periodarr_to_dt64arr(new_data.values, base)
         return DatetimeIndex(new_data, freq='infer', name=self.name)

pandas/tseries/tests/test_period.py

@@ -1202,12 +1202,12 @@ def test_to_timestamp(self):
         series = Series(1, index=index, name='foo')
 
         exp_index = date_range('1/1/2001', end='12/31/2009', freq='A-DEC')
-        result = series.to_timestamp('D', 'end')
+        result = series.to_timestamp(how='end')
         self.assert_(result.index.equals(exp_index))
         self.assertEquals(result.name, 'foo')
 
         exp_index = date_range('1/1/2001', end='1/1/2009', freq='AS-DEC')
-        result = series.to_timestamp('D', 'start')
+        result = series.to_timestamp(how='start')
         self.assert_(result.index.equals(exp_index))
 
 
@@ -1232,6 +1232,15 @@ def _get_with_delta(delta, freq='A-DEC'):
 
         self.assertRaises(ValueError, index.to_timestamp, '5t')
 
+        index = PeriodIndex(freq='H', start='1/1/2001', end='1/2/2001')
+        series = Series(1, index=index, name='foo')
+
+        exp_index = date_range('1/1/2001 00:59:59', end='1/2/2001 00:59:59',
+                               freq='H')
+        result = series.to_timestamp(how='end')
+        self.assert_(result.index.equals(exp_index))
+        self.assertEquals(result.name, 'foo')
+
     def test_to_timestamp_quarterly_bug(self):
         years = np.arange(1960, 2000).repeat(4)
         quarters = np.tile(range(1, 5), 40)