Merge pull request #3630 from jseabold/series-sort-ascending

ENH: Add Series.sort ascending keyword

Author: jreback

pandas/core/series.py

@@ -2012,7 +2012,7 @@ def dot(self, other):
 
         Parameters
         ----------
-        other : Series or DataFrame 
+        other : Series or DataFrame
 
         Returns
         -------
@@ -2194,7 +2194,7 @@ def update(self, other):
     #----------------------------------------------------------------------
     # Reindexing, sorting
 
-    def sort(self, axis=0, kind='quicksort', order=None):
+    def sort(self, axis=0, kind='quicksort', order=None, ascending=True):
         """
         Sort values and index labels by value, in place. For compatibility with
         ndarray API. No return value
@@ -2206,8 +2206,15 @@ def sort(self, axis=0, kind='quicksort', order=None):
             Choice of sorting algorithm. See np.sort for more
             information. 'mergesort' is the only stable algorithm
         order : ignored
+        ascending : boolean, default True
+            Sort ascending. Passing False sorts descending
+
+        See Also
+        --------
+        pandas.Series.order
         """
-        sortedSeries = self.order(na_last=True, kind=kind)
+        sortedSeries = self.order(na_last=True, kind=kind,
+                                  ascending=ascending)
 
         true_base = self
         while true_base.base is not None:

pandas/tests/test_series.py

@@ -475,7 +475,7 @@ def test_constructor_dtype_datetime64(self):
             np.datetime64(datetime(2013, 1, 2)),
             np.datetime64(datetime(2013, 1, 3)),
             ]
-        
+
         s = Series(dates)
         self.assert_(s.dtype == 'M8[ns]')
 
@@ -1162,7 +1162,7 @@ def test_where(self):
             s = Series(np.arange(10), dtype=dtype)
             mask = s < 5
             values = [2.5,3.5,4.5,5.5,6.5]
-            s[mask] = values 
+            s[mask] = values
             expected = Series(values + range(5,10), dtype='float64')
             assert_series_equal(s, expected)
             self.assertEquals(s.dtype, expected.dtype)
@@ -2591,7 +2591,7 @@ def test_dot(self):
         expected = Series(np.dot(a.values, b.values),
                              index=['1', '2', '3'])
         assert_series_equal(result, expected)
-        
+
         #Check index alignment
         b2 = b.reindex(index=reversed(b.index))
         result = a.dot(b)
@@ -2723,6 +2723,11 @@ def test_sort(self):
         self.assert_(np.array_equal(ts, self.ts.order()))
         self.assert_(np.array_equal(ts.index, self.ts.order().index))
 
+        ts.sort(ascending=False)
+        self.assert_(np.array_equal(ts, self.ts.order(ascending=False)))
+        self.assert_(np.array_equal(ts.index,
+                                    self.ts.order(ascending=False).index))
+
     def test_sort_index(self):
         import random