BUG: np.timedelta64 + Period (#44182)

doc/source/whatsnew/v1.4.0.rst

@@ -567,7 +567,7 @@ I/O
 
 Period
 ^^^^^^
--
+- Bug in adding a :class:`Period` object to a ``np.timedelta64`` object incorrectly raising ``TypeError`` (:issue:`44182`)
 -
 
 Plotting

pandas/_libs/tslibs/period.pyx

@@ -4,6 +4,7 @@ cimport numpy as cnp
 from cpython.object cimport (
     Py_EQ,
     Py_NE,
+    PyObject_RichCompare,
     PyObject_RichCompareBool,
 )
 from numpy cimport (
@@ -1594,6 +1595,9 @@ cdef class _Period(PeriodMixin):
         PeriodDtypeBase _dtype
         BaseOffset freq
 
+    # higher than np.ndarray, np.matrix, np.timedelta64
+    __array_priority__ = 100
+
     dayofweek = _Period.day_of_week
     dayofyear = _Period.day_of_year
 
@@ -1652,7 +1656,10 @@ cdef class _Period(PeriodMixin):
             return PyObject_RichCompareBool(self.ordinal, other.ordinal, op)
         elif other is NaT:
             return _nat_scalar_rules[op]
-        return NotImplemented  # TODO: ndarray[object]?
+        elif util.is_array(other):
+            # in particular ndarray[object]; see test_pi_cmp_period
+            return np.array([PyObject_RichCompare(self, x, op) for x in other])
+        return NotImplemented
 
     def __hash__(self):
         return hash((self.ordinal, self.freqstr))

pandas/tests/arithmetic/test_period.py

@@ -185,6 +185,10 @@ def test_pi_cmp_period(self):
         exp = idx.values < idx.values[10]
         tm.assert_numpy_array_equal(result, exp)
 
+        # Tests Period.__richcmp__ against ndarray[object, ndim=2]
+        result = idx.values.reshape(10, 2) < idx[10]
+        tm.assert_numpy_array_equal(result, exp.reshape(10, 2))
+
     # TODO: moved from test_datetime64; de-duplicate with version below
     def test_parr_cmp_period_scalar2(self, box_with_array):
         xbox = get_expected_box(box_with_array)

pandas/tests/scalar/period/test_period.py

@@ -1287,20 +1287,8 @@ def test_add_offset(self):
                 msg = "Input has different freq|Input cannot be converted to Period"
                 with pytest.raises(IncompatibleFrequency, match=msg):
                     p + o
-
-                if isinstance(o, np.timedelta64):
-                    msg = "cannot use operands with types"
-                    with pytest.raises(TypeError, match=msg):
-                        o + p
-                else:
-                    msg = "|".join(
-                        [
-                            "Input has different freq",
-                            "Input cannot be converted to Period",
-                        ]
-                    )
-                    with pytest.raises(IncompatibleFrequency, match=msg):
-                        o + p
+                with pytest.raises(IncompatibleFrequency, match=msg):
+                    o + p
 
         for freq in ["M", "2M", "3M"]:
             p = Period("2011-03", freq=freq)
@@ -1329,14 +1317,8 @@ def test_add_offset(self):
 
                 with pytest.raises(IncompatibleFrequency, match=msg):
                     p + o
-
-                if isinstance(o, np.timedelta64):
-                    td_msg = "cannot use operands with types"
-                    with pytest.raises(TypeError, match=td_msg):
-                        o + p
-                else:
-                    with pytest.raises(IncompatibleFrequency, match=msg):
-                        o + p
+                with pytest.raises(IncompatibleFrequency, match=msg):
+                    o + p
 
         # freq is Tick
         for freq in ["D", "2D", "3D"]:
@@ -1352,14 +1334,11 @@ def test_add_offset(self):
 
             exp = Period("2011-04-03", freq=freq)
             assert p + np.timedelta64(2, "D") == exp
-            msg = "cannot use operands with types"
-            with pytest.raises(TypeError, match=msg):
-                np.timedelta64(2, "D") + p
+            assert np.timedelta64(2, "D") + p == exp
 
             exp = Period("2011-04-02", freq=freq)
             assert p + np.timedelta64(3600 * 24, "s") == exp
-            with pytest.raises(TypeError, match=msg):
-                np.timedelta64(3600 * 24, "s") + p
+            assert np.timedelta64(3600 * 24, "s") + p == exp
 
             exp = Period("2011-03-30", freq=freq)
             assert p + timedelta(-2) == exp
@@ -1385,14 +1364,8 @@ def test_add_offset(self):
             ]:
                 with pytest.raises(IncompatibleFrequency, match=msg):
                     p + o
-
-                if isinstance(o, np.timedelta64):
-                    td_msg = "cannot use operands with types"
-                    with pytest.raises(TypeError, match=td_msg):
-                        o + p
-                else:
-                    with pytest.raises(IncompatibleFrequency, match=msg):
-                        o + p
+                with pytest.raises(IncompatibleFrequency, match=msg):
+                    o + p
 
         for freq in ["H", "2H", "3H"]:
             p = Period("2011-04-01 09:00", freq=freq)
@@ -1408,13 +1381,11 @@ def test_add_offset(self):
             msg = "cannot use operands with types"
             exp = Period("2011-04-01 12:00", freq=freq)
             assert p + np.timedelta64(3, "h") == exp
-            with pytest.raises(TypeError, match=msg):
-                np.timedelta64(3, "h") + p
+            assert np.timedelta64(3, "h") + p == exp
 
             exp = Period("2011-04-01 10:00", freq=freq)
             assert p + np.timedelta64(3600, "s") == exp
-            with pytest.raises(TypeError, match=msg):
-                np.timedelta64(3600, "s") + p
+            assert np.timedelta64(3600, "s") + p == exp
 
             exp = Period("2011-04-01 11:00", freq=freq)
             assert p + timedelta(minutes=120) == exp
@@ -1440,14 +1411,8 @@ def test_add_offset(self):
             ]:
                 with pytest.raises(IncompatibleFrequency, match=msg):
                     p + o
-
-                if isinstance(o, np.timedelta64):
-                    td_msg = "cannot use operands with types"
-                    with pytest.raises(TypeError, match=td_msg):
-                        o + p
-                else:
-                    with pytest.raises(IncompatibleFrequency, match=msg):
-                        o + p
+                with pytest.raises(IncompatibleFrequency, match=msg):
+                    o + p
 
     def test_sub_offset(self):
         # freq is DateOffset