API: Timedelta constructor from keywords give microseconds

pandas/_libs/tslibs/timedeltas.pyx

@@ -2045,7 +2045,7 @@ class Timedelta(_Timedelta):
                     int(ns)
                     + int(us * 1_000)
                     + int(ms * 1_000_000)
-                    + seconds
+                    + seconds, "ns"
                 )
             except OverflowError as err:
                 # GH#55503
@@ -2055,6 +2055,13 @@ class Timedelta(_Timedelta):
                 )
                 raise OutOfBoundsTimedelta(msg) from err
 
+            if (
+                "nanoseconds" not in kwargs
+                and cnp.get_timedelta64_value(value) % 1000 == 0
+            ):
+                # If possible, give a microsecond unit
+                value = value.astype("m8[us]")
+
         disallow_ambiguous_unit(unit)
 
         cdef:

pandas/conftest.py

@@ -938,7 +938,7 @@ def rand_series_with_duplicate_datetimeindex() -> Series:
             Timestamp("2011-01-01", tz="US/Eastern").as_unit("s"),
             DatetimeTZDtype(unit="s", tz="US/Eastern"),
         ),
-        (Timedelta(seconds=500), "timedelta64[ns]"),
+        (Timedelta(seconds=500), "timedelta64[us]"),
     ]
 )
 def ea_scalar_and_dtype(request):

pandas/tests/arithmetic/test_numeric.py

@@ -223,8 +223,8 @@ def test_div_td64arr(self, left, box_cls):
     @pytest.mark.parametrize(
         "scalar_td",
         [
-            Timedelta(days=1),
-            Timedelta(days=1).to_timedelta64(),
+            Timedelta(days=1).as_unit("ns"),
+            Timedelta(days=1).as_unit("ns").to_timedelta64(),
             Timedelta(days=1).to_pytimedelta(),
             Timedelta(days=1).to_timedelta64().astype("timedelta64[s]"),
             Timedelta(days=1).to_timedelta64().astype("timedelta64[ms]"),
@@ -254,9 +254,9 @@ def test_numeric_arr_mul_tdscalar(self, scalar_td, numeric_idx, box_with_array):
     @pytest.mark.parametrize(
         "scalar_td",
         [
-            Timedelta(days=1),
-            Timedelta(days=1).to_timedelta64(),
-            Timedelta(days=1).to_pytimedelta(),
+            Timedelta(days=1).as_unit("ns"),
+            Timedelta(days=1).as_unit("ns").to_timedelta64(),
+            Timedelta(days=1).as_unit("ns").to_pytimedelta(),
         ],
         ids=lambda x: type(x).__name__,
     )

pandas/tests/base/test_value_counts.py

@@ -359,7 +359,7 @@ def test_value_counts_object_inference_deprecated():
                 + [Timestamp("2016-01-02")]
                 + [Timestamp("2016-01-01") + Timedelta(days=i) for i in range(1, 5)]
             ),
-            DatetimeIndex(pd.date_range("2016-01-01", periods=5, freq="D")),
+            DatetimeIndex(pd.date_range("2016-01-01", periods=5, freq="D", unit="us")),
         ],
         [
             TimedeltaIndex(

pandas/tests/scalar/timedelta/methods/test_as_unit.py

@@ -10,29 +10,29 @@ class TestAsUnit:
     def test_as_unit(self):
         td = Timedelta(days=1)
 
-        assert td.as_unit("ns") is td
+        assert td.as_unit("us") is td
 
-        res = td.as_unit("us")
-        assert res._value == td._value // 1000
-        assert res._creso == NpyDatetimeUnit.NPY_FR_us.value
+        res = td.as_unit("ns")
+        assert res._value == td._value * 1000
+        assert res._creso == NpyDatetimeUnit.NPY_FR_ns.value
 
-        rt = res.as_unit("ns")
+        rt = res.as_unit("us")
         assert rt._value == td._value
         assert rt._creso == td._creso
 
         res = td.as_unit("ms")
-        assert res._value == td._value // 1_000_000
+        assert res._value == td._value // 1_000
         assert res._creso == NpyDatetimeUnit.NPY_FR_ms.value
 
-        rt = res.as_unit("ns")
+        rt = res.as_unit("us")
         assert rt._value == td._value
         assert rt._creso == td._creso
 
         res = td.as_unit("s")
-        assert res._value == td._value // 1_000_000_000
+        assert res._value == td._value // 1_000_000
         assert res._creso == NpyDatetimeUnit.NPY_FR_s.value
 
-        rt = res.as_unit("ns")
+        rt = res.as_unit("us")
         assert rt._value == td._value
         assert rt._creso == td._creso
 

pandas/tests/scalar/timedelta/test_arithmetic.py

@@ -818,11 +818,11 @@ def test_mod_numeric(self):
         assert isinstance(result, Timedelta)
         assert result == Timedelta(0)
 
-        result = td % 1e12
+        result = td % 1e9
         assert isinstance(result, Timedelta)
         assert result == Timedelta(minutes=3, seconds=20)
 
-        result = td % int(1e12)
+        result = td % int(1e9)
         assert isinstance(result, Timedelta)
         assert result == Timedelta(minutes=3, seconds=20)
 
@@ -876,8 +876,8 @@ def test_divmod_numeric(self):
         # GH#19365
         td = Timedelta(days=2, hours=6)
 
-        result = divmod(td, 53 * 3600 * 1e9)
-        assert result[0] == Timedelta(1, unit="ns")
+        result = divmod(td, 53 * 3600 * 1e6)
+        assert result[0] == Timedelta(1, unit="us").as_unit("us")
         assert isinstance(result[1], Timedelta)
         assert result[1] == Timedelta(hours=1)
 

pandas/tests/scalar/timedelta/test_constructors.py

@@ -272,14 +272,14 @@ def test_construction():
     assert Timedelta(10, unit="D")._value == expected
     assert Timedelta(10.0, unit="D")._value == expected
     assert Timedelta("10 days")._value == expected
-    assert Timedelta(days=10)._value == expected
-    assert Timedelta(days=10.0)._value == expected
+    assert Timedelta(days=10)._value == expected // 1000
+    assert Timedelta(days=10.0)._value == expected // 1000
 
     expected += np.timedelta64(10, "s").astype("m8[ns]").view("i8")
     assert Timedelta("10 days 00:00:10")._value == expected
-    assert Timedelta(days=10, seconds=10)._value == expected
-    assert Timedelta(days=10, milliseconds=10 * 1000)._value == expected
-    assert Timedelta(days=10, microseconds=10 * 1000 * 1000)._value == expected
+    assert Timedelta(days=10, seconds=10)._value == expected // 1000
+    assert Timedelta(days=10, milliseconds=10 * 1000)._value == expected // 1000
+    assert Timedelta(days=10, microseconds=10 * 1000 * 1000)._value == expected // 1000
 
     # rounding cases
     assert Timedelta(82739999850000)._value == 82739999850000
@@ -411,7 +411,7 @@ def test_construction():
 def test_td_construction_with_np_dtypes(npdtype, item):
     # GH#8757: test construction with np dtypes
     pykwarg, npkwarg = item
-    expected = np.timedelta64(1, npkwarg).astype("m8[ns]").view("i8")
+    expected = np.timedelta64(1, npkwarg).astype("m8[us]").view("i8")
     assert Timedelta(**{pykwarg: npdtype(1)})._value == expected
 
 

pandas/tests/scalar/timedelta/test_timedelta.py

@@ -664,7 +664,7 @@ def test_resolution_deprecated(self):
         # GH#21344
         td = Timedelta(days=4, hours=3)
         result = td.resolution
-        assert result == Timedelta(nanoseconds=1)
+        assert result == Timedelta(microseconds=1)
 
         # Check that the attribute is available on the class, mirroring
         #  the stdlib timedelta behavior

pandas/tests/tseries/offsets/test_common.py

@@ -150,7 +150,7 @@ def test_apply_out_of_range(request, tz_naive_fixture, _offset):
             request.applymarker(
                 pytest.mark.xfail(reason="After GH#49737 t.tzinfo is None on CI")
             )
-        assert str(t.tzinfo) == str(result.tzinfo)
+        assert str(t.tzinfo) == str(result.tzinfo), (t.tzinfo, result.tzinfo)
 
     except OutOfBoundsDatetime:
         pass