BUG: Timestamp cmp ndarray[dt64] (#33346)

Author: jbrockmendel

pandas/_libs/tslibs/c_timestamp.pyx

@@ -114,6 +114,18 @@ cdef class _Timestamp(datetime):
                         return NotImplemented
                 elif is_array(other):
                     # avoid recursion error GH#15183
+                    if other.dtype.kind == "M":
+                        if self.tz is None:
+                            return PyObject_RichCompare(self.asm8, other, op)
+                        raise TypeError(
+                            "Cannot compare tz-naive and tz-aware timestamps"
+                        )
+                    if other.dtype.kind == "O":
+                        # Operate element-wise
+                        return np.array(
+                            [PyObject_RichCompare(self, x, op) for x in other],
+                            dtype=bool,
+                        )
                     return PyObject_RichCompare(np.array([self]), other, op)
                 return PyObject_RichCompare(other, self, reverse_ops[op])
             else:

pandas/tests/scalar/timestamp/test_comparisons.py

@@ -5,9 +5,61 @@
 import pytest
 
 from pandas import Timestamp
+import pandas._testing as tm
 
 
 class TestTimestampComparison:
+    def test_comparison_dt64_ndarray(self):
+        ts = Timestamp.now()
+        ts2 = Timestamp("2019-04-05")
+        arr = np.array([[ts.asm8, ts2.asm8]], dtype="M8[ns]")
+
+        result = ts == arr
+        expected = np.array([[True, False]], dtype=bool)
+        tm.assert_numpy_array_equal(result, expected)
+
+        result = arr == ts
+        tm.assert_numpy_array_equal(result, expected)
+
+        result = ts != arr
+        tm.assert_numpy_array_equal(result, ~expected)
+
+        result = arr != ts
+        tm.assert_numpy_array_equal(result, ~expected)
+
+        result = ts2 < arr
+        tm.assert_numpy_array_equal(result, expected)
+
+        result = arr < ts2
+        tm.assert_numpy_array_equal(result, np.array([[False, False]], dtype=bool))
+
+        result = ts2 <= arr
+        tm.assert_numpy_array_equal(result, np.array([[True, True]], dtype=bool))
+
+        result = arr <= ts2
+        tm.assert_numpy_array_equal(result, ~expected)
+
+        result = ts >= arr
+        tm.assert_numpy_array_equal(result, np.array([[True, True]], dtype=bool))
+
+        result = arr >= ts
+        tm.assert_numpy_array_equal(result, np.array([[True, False]], dtype=bool))
+
+    @pytest.mark.parametrize("reverse", [True, False])
+    def test_comparison_dt64_ndarray_tzaware(self, reverse, all_compare_operators):
+        op = getattr(operator, all_compare_operators.strip("__"))
+
+        ts = Timestamp.now("UTC")
+        arr = np.array([ts.asm8, ts.asm8], dtype="M8[ns]")
+
+        left, right = ts, arr
+        if reverse:
+            left, right = arr, ts
+
+        msg = "Cannot compare tz-naive and tz-aware timestamps"
+        with pytest.raises(TypeError, match=msg):
+            op(left, right)
+
     def test_comparison_object_array(self):
         # GH#15183
         ts = Timestamp("2011-01-03 00:00:00-0500", tz="US/Eastern")