BUG: Fix _binop for operators for serials which has more than one returns (divmod/rdivmod).

doc/source/whatsnew/v0.24.2.rst

@@ -31,6 +31,7 @@ Fixed Regressions
 - Fixed regression in ``IntervalDtype`` construction where passing an incorrect string with 'Interval' as a prefix could result in a ``RecursionError``. (:issue:`25338`)
 - Fixed regression in :class:`Categorical`, where constructing it from a categorical ``Series`` and an explicit ``categories=`` that differed from that in the ``Series`` created an invalid object which could trigger segfaults. (:issue:`25318`)
 - Fixed pip installing from source into an environment without NumPy (:issue:`25193`)
+- Fixed bug in :meth:`Series._binop` to handle binary operators that returns more than one :class:`Series` correctly (:issue:`25557`)
 
 .. _whatsnew_0242.enhancements:
 

pandas/core/series.py

@@ -2502,6 +2502,15 @@ def _binop(self, other, func, level=None, fill_value=None):
         -------
         Series
         """
+
+        def mk_ret(result, new_index, name):
+            ret = self._constructor(result, index=new_index, name=name)
+            ret.__finalize__(self)
+            if name is None:
+                # When name is None, __finalize__ overwrites current name
+                ret.name = None
+            return ret
+
         if not isinstance(other, Series):
             raise AssertionError('Other operand must be Series')
 
@@ -2519,12 +2528,13 @@ def _binop(self, other, func, level=None, fill_value=None):
         with np.errstate(all='ignore'):
             result = func(this_vals, other_vals)
         name = ops.get_op_result_name(self, other)
-        result = self._constructor(result, index=new_index, name=name)
-        result = result.__finalize__(self)
-        if name is None:
-            # When name is None, __finalize__ overwrites current name
-            result.name = None
-        return result
+        if isinstance(result, tuple):
+            final_result = ()
+            for r in result:
+                final_result = (*final_result, mk_ret(r, new_index, name))
+        else:
+            final_result = mk_ret(result, new_index, name)
+        return final_result
 
     def combine(self, other, func, fill_value=None):
         """

pandas/tests/series/test_operators.py

@@ -741,6 +741,20 @@ def test_op_duplicate_index(self):
         expected = pd.Series([11, 12, np.nan], index=[1, 1, 2])
         assert_series_equal(result, expected)
 
+    def test_divmod(self):
+        a = Series([1, 1, 1, np.nan], index=['a', 'b', 'c', 'd'])
+        b = Series([2, np.nan, 1, np.nan], index=['a', 'b', 'd', 'e'])
+
+        r1 = divmod(a, b)
+        r2 = a.divmod(b)
+        assert_series_equal(r1[0], r2[0])
+        assert_series_equal(r1[1], r2[1])
+
+        r3 = divmod(b, a)
+        r4 = a.rdivmod(b)
+        assert_series_equal(r3[0], r4[0])
+        assert_series_equal(r3[1], r4[1])
+
 
 class TestSeriesUnaryOps(object):
     # __neg__, __pos__, __inv__