Merge pull request #10960 from terrytangyuan/PR2update

BUG: Fixed bug that Timedelta raises error when slicing from 0s (issue #10583)

Author: jreback

doc/source/whatsnew/v0.17.0.txt

@@ -822,6 +822,7 @@ Bug Fixes
 - Bug in ``pd.DataFrame`` when constructing an empty DataFrame with a string dtype (:issue:`9428`)
 - Bug in ``pd.DataFrame.diff`` when DataFrame is not consolidated (:issue:`10907`)
 - Bug in ``pd.unique`` for arrays with the ``datetime64`` or ``timedelta64`` dtype that meant an array with object dtype was returned instead the original dtype (:issue:`9431`)
+- Bug in ``Timedelta`` raising error when slicing from 0s (:issue:`10583`)
 - Bug in ``DatetimeIndex.take`` and ``TimedeltaIndex.take`` may not raise ``IndexError`` against invalid index (:issue:`10295`)
 - Bug in ``Series([np.nan]).astype('M8[ms]')``, which now returns ``Series([pd.NaT])`` (:issue:`10747`)
 - Bug in ``PeriodIndex.order`` reset freq (:issue:`10295`)

pandas/tseries/tests/test_timedeltas.py

@@ -404,6 +404,14 @@ def test_timedelta_range(self):
         result = timedelta_range('0 days',freq='30T',periods=50)
         tm.assert_index_equal(result, expected)
 
+        # issue10583
+        df = pd.DataFrame(np.random.normal(size=(10,4)))
+        df.index = pd.timedelta_range(start='0s', periods=10, freq='s')
+        expected = df.loc[pd.Timedelta('0s'):,:]
+        result = df.loc['0s':,:]
+        assert_frame_equal(expected, result)
+
+
     def test_numeric_conversions(self):
         self.assertEqual(ct(0), np.timedelta64(0,'ns'))
         self.assertEqual(ct(10), np.timedelta64(10,'ns'))

pandas/tslib.pyx

@@ -2265,9 +2265,8 @@ class Timedelta(_Timedelta):
            return "m"
         elif self._h:
            return "h"
-        elif self._d:
+        else:
            return "D"
-        raise ValueError("invalid resolution")
 
     def round(self, reso):
         """