Fix Timedelta floordiv, rfloordiv with offset, fix td64 return types (#19770)

Author: jbrockmendel

doc/source/whatsnew/v0.23.0.txt

@@ -730,6 +730,8 @@ Datetimelike
 - Bug in :class:`Timestamp` and :func:`to_datetime` where a string representing a barely out-of-bounds timestamp would be incorrectly rounded down instead of raising ``OutOfBoundsDatetime`` (:issue:`19382`)
 - Bug in :func:`Timestamp.floor` :func:`DatetimeIndex.floor` where time stamps far in the future and past were not rounded correctly (:issue:`19206`)
 - Bug in :func:`to_datetime` where passing an out-of-bounds datetime with ``errors='coerce'`` and ``utc=True`` would raise ``OutOfBoundsDatetime`` instead of parsing to ``NaT`` (:issue:`19612`)
+- Bug in :func:`Timedelta.__add__`, :func:`Timedelta.__sub__` where adding or subtracting a ``np.timedelta64`` object would return another ``np.timedelta64`` instead of a ``Timedelta`` (:issue:`19738`)
+- Bug in :func:`Timedelta.__floordiv__`, :func:`Timedelta.__rfloordiv__` where operating with a ``Tick`` object would raise a ``TypeError`` instead of returning a numeric value (:issue:`19738`)
 -
 
 Timezones

pandas/_libs/tslibs/timedeltas.pyx

@@ -478,11 +478,16 @@ def _binary_op_method_timedeltalike(op, name):
         elif other is NaT:
             return NaT
 
+        elif is_timedelta64_object(other):
+            # convert to Timedelta below; avoid catching this in
+            # has-dtype check before then
+            pass
+
         elif is_datetime64_object(other) or PyDateTime_CheckExact(other):
             # the PyDateTime_CheckExact case is for a datetime object that
             # is specifically *not* a Timestamp, as the Timestamp case will be
             # handled after `_validate_ops_compat` returns False below
-            from ..tslib import Timestamp
+            from timestamps import Timestamp
             return op(self, Timestamp(other))
             # We are implicitly requiring the canonical behavior to be
             # defined by Timestamp methods.
@@ -503,6 +508,9 @@ def _binary_op_method_timedeltalike(op, name):
             # failed to parse as timedelta
             return NotImplemented
 
+        if other is NaT:
+            # e.g. if original other was timedelta64('NaT')
+            return NaT
         return Timedelta(op(self.value, other.value), unit='ns')
 
     f.__name__ = name
@@ -1096,6 +1104,9 @@ class Timedelta(_Timedelta):
         # just defer
         if hasattr(other, '_typ'):
             # Series, DataFrame, ...
+            if other._typ == 'dateoffset' and hasattr(other, 'delta'):
+                # Tick offset
+                return self // other.delta
             return NotImplemented
 
         if hasattr(other, 'dtype'):
@@ -1128,6 +1139,9 @@ class Timedelta(_Timedelta):
         # just defer
         if hasattr(other, '_typ'):
             # Series, DataFrame, ...
+            if other._typ == 'dateoffset' and hasattr(other, 'delta'):
+                # Tick offset
+                return other.delta // self
             return NotImplemented
 
         if hasattr(other, 'dtype'):

pandas/tests/scalar/timedelta/test_arithmetic.py

@@ -100,7 +100,6 @@ def test_td_add_pytimedelta(self, op):
         assert isinstance(result, Timedelta)
         assert result == Timedelta(days=19)
 
-    @pytest.mark.xfail(reason='GH#19738 argument not converted to Timedelta')
     @pytest.mark.parametrize('op', [operator.add, ops.radd])
     def test_td_add_timedelta64(self, op):
         td = Timedelta(10, unit='d')
@@ -130,21 +129,18 @@ def test_td_sub_pytimedelta(self):
         assert isinstance(result, Timedelta)
         assert result == expected
 
-    @pytest.mark.xfail(reason='GH#19738 argument not converted to Timedelta')
     def test_td_sub_timedelta64(self):
         td = Timedelta(10, unit='d')
         expected = Timedelta(0, unit='ns')
         result = td - td.to_timedelta64()
         assert isinstance(result, Timedelta)
-        # comparison fails even if we comment out the isinstance assertion
         assert result == expected
 
     def test_td_sub_nat(self):
         td = Timedelta(10, unit='d')
         result = td - NaT
         assert result is NaT
 
-    @pytest.mark.xfail(reason='GH#19738 argument not converted to Timedelta')
     def test_td_sub_td64_nat(self):
         td = Timedelta(10, unit='d')
         result = td - np.timedelta64('NaT')
@@ -171,7 +167,6 @@ def test_td_rsub_pytimedelta(self):
         assert isinstance(result, Timedelta)
         assert result == expected
 
-    @pytest.mark.xfail(reason='GH#19738 argument not converted to Timedelta')
     def test_td_rsub_timedelta64(self):
         td = Timedelta(10, unit='d')
         expected = Timedelta(0, unit='ns')
@@ -188,7 +183,6 @@ def test_td_rsub_nat(self):
         result = np.datetime64('NaT') - td
         assert result is NaT
 
-    @pytest.mark.xfail(reason='GH#19738 argument not converted to Timedelta')
     def test_td_rsub_td64_nat(self):
         td = Timedelta(10, unit='d')
         result = np.timedelta64('NaT') - td
@@ -304,6 +298,12 @@ def test_td_floordiv_null_scalar(self):
         assert np.isnan(td // NaT)
         assert np.isnan(td // np.timedelta64('NaT'))
 
+    def test_td_floordiv_offsets(self):
+        # GH#19738
+        td = Timedelta(hours=3, minutes=4)
+        assert td // pd.offsets.Hour(1) == 3
+        assert td // pd.offsets.Minute(2) == 92
+
     def test_td_floordiv_invalid_scalar(self):
         # GH#18846
         td = Timedelta(hours=3, minutes=4)
@@ -322,7 +322,7 @@ def test_td_floordiv_numeric_scalar(self):
         assert td // np.int32(2.0) == expected
         assert td // np.uint8(2.0) == expected
 
-    def test_floordiv_timedeltalike_array(self):
+    def test_td_floordiv_timedeltalike_array(self):
         # GH#18846
         td = Timedelta(hours=3, minutes=4)
         scalar = Timedelta(hours=3, minutes=3)
@@ -371,6 +371,10 @@ def test_td_rfloordiv_null_scalar(self):
         assert np.isnan(td.__rfloordiv__(NaT))
         assert np.isnan(td.__rfloordiv__(np.timedelta64('NaT')))
 
+    def test_td_rfloordiv_offsets(self):
+        # GH#19738
+        assert pd.offsets.Hour(1) // Timedelta(minutes=25) == 2
+
     def test_td_rfloordiv_invalid_scalar(self):
         # GH#18846
         td = Timedelta(hours=3, minutes=3)