Improved tests & addressed comments

pandas/core/resample.py

@@ -17,7 +17,7 @@
 from pandas.core.indexes.period import PeriodIndex, period_range
 import pandas.core.common as com
 import pandas.core.algorithms as algos
-from pandas.core.dtypes.generic import ABCDataFrame
+from pandas.core.dtypes.generic import ABCDataFrame, ABCSeries
 
 import pandas.compat as compat
 from pandas.compat.numpy import function as nv
@@ -439,6 +439,11 @@ def _wrap_result(self, result):
         if isinstance(result, com.ABCSeries) and self._selection is not None:
             result.name = self._selection
 
+        if isinstance(result, ABCSeries) and result.empty:
+            obj = self.obj
+            result.index = obj.index._shallow_copy(freq=to_offset(self.freq))
+            result.name = getattr(obj, 'name', None)
+
         return result
 
     def pad(self, limit=None):
@@ -778,11 +783,6 @@ def _wrap_result(self, result):
         # convert if needed
         if self.kind == 'period' and not isinstance(result.index, PeriodIndex):
             result.index = result.index.to_period(self.freq)
-
-        if isinstance(result, com.ABCSeries) and result.empty:
-            obj = self.obj
-            result.index = obj.index._shallow_copy(freq=to_offset(self.freq))
-            result.name = getattr(obj, 'name', None)
         return result
 
 

pandas/tests/test_resample.py

@@ -852,6 +852,16 @@ def test_resample_loffset_arg_type(self):
                 assert_frame_equal(result_agg, expected)
                 assert_frame_equal(result_how, expected)
 
+    def test_apply_to_empty_series(self):
+        # GH 14313
+        series = self.create_series()[:0]
+
+        for freq in ['M', 'D', 'H']:
+            result = series.resample(freq).apply(lambda x: 1)
+            expected = series.resample(freq).apply(np.sum)
+
+            assert_series_equal(result, expected, check_dtype=False)
+
 
 class TestDatetimeIndex(Base):
     _index_factory = lambda x: date_range
@@ -2192,17 +2202,6 @@ def test_resample_datetime_values(self):
         res = df['timestamp'].resample('2D').first()
         tm.assert_series_equal(res, exp)
 
-    def test_apply_to_empty_series(self):
-        # GH 14313
-        series = self.create_series()[:0]
-
-        for freq in ['M', 'D', 'H']:
-            result = series.resample(freq).apply(lambda x: 1)
-            expected = series.resample(freq).apply(np.sum)
-
-            assert result.name == expected.name
-            assert_series_equal(result, expected, check_dtype=False)
-
 
 class TestPeriodIndex(Base):
     _index_factory = lambda x: period_range
@@ -2805,6 +2804,14 @@ def test_evenly_divisible_with_no_extra_bins(self):
         result = df.resample('7D').sum()
         assert_frame_equal(result, expected)
 
+    def test_apply_to_empty_series(self):
+        # GH 14313
+        series = self.create_series()[:0]
+
+        for freq in ['M', 'D', 'H']:
+            with pytest.raises(TypeError):
+                series.resample(freq).apply(lambda x: 1)
+
 
 class TestTimedeltaIndex(Base):
     _index_factory = lambda x: timedelta_range