Merge pull request #4813 from jreback/dup_resample

TST: tests for GH4812 (already fixed in master)

Author: jreback

pandas/tseries/tests/test_resample.py

@@ -284,6 +284,17 @@ def test_resample_ohlc_dataframe(self):
         # dupe columns fail atm
         # df.columns = ['PRICE', 'PRICE']
 
+    def test_resample_dup_index(self):
+
+        # GH 4812
+        # dup columns with resample raising
+        df = DataFrame(np.random.randn(4,12),index=[2000,2000,2000,2000],columns=[ Period(year=2000,month=i+1,freq='M') for i in range(12) ])
+        df.iloc[3,:] = np.nan
+        result = df.resample('Q',axis=1)
+        expected = df.groupby(lambda x: int((x.month-1)/3),axis=1).mean()
+        expected.columns = [ Period(year=2000,quarter=i+1,freq='Q') for i in range(4) ]
+        assert_frame_equal(result, expected)
+
     def test_resample_reresample(self):
         dti = DatetimeIndex(
             start=datetime(2005, 1, 1), end=datetime(2005, 1, 10),