update tests

Author: jbrockmendel

pandas/tests/io/excel/test_readers.py

@@ -1130,17 +1130,18 @@ def test_read_excel_multiindex_blank_after_name(
 
         expected = DataFrame(
             [
-                [1, 2.5, pd.Timestamp("2015-01-01").as_unit(unit), True],
-                [2, 3.5, pd.Timestamp("2015-01-02").as_unit(unit), False],
-                [3, 4.5, pd.Timestamp("2015-01-03").as_unit(unit), False],
-                [4, 5.5, pd.Timestamp("2015-01-04").as_unit(unit), True],
+                [1, 2.5, pd.Timestamp("2015-01-01"), True],
+                [2, 3.5, pd.Timestamp("2015-01-02"), False],
+                [3, 4.5, pd.Timestamp("2015-01-03"), False],
+                [4, 5.5, pd.Timestamp("2015-01-04"), True],
             ],
             columns=mi,
             index=MultiIndex.from_arrays(
                 (["foo", "foo", "bar", "bar"], idx_lvl2),
                 names=["ilvl1", "ilvl2"],
             ),
         )
+        expected[mi[2]] = expected[mi[2]].astype(f"M8[{unit}]")
         result = pd.read_excel(
             mi_file,
             sheet_name=sheet_name,

pandas/tests/io/parser/common/test_common_basic.py

@@ -112,8 +112,9 @@ def test_read_csv_local(all_parsers, csv1):
                 datetime(2000, 1, 10),
                 datetime(2000, 1, 11),
             ],
+            dtype="M8[s]",
             name="index",
-        ).as_unit("s"),
+        ),
     )
     tm.assert_frame_equal(result, expected)
 
@@ -213,8 +214,9 @@ def test_read_csv_dataframe(all_parsers, csv1):
                 datetime(2000, 1, 10),
                 datetime(2000, 1, 11),
             ],
+            dtype="M8[s]",
             name="index",
-        ).as_unit("s"),
+        ),
     )
     tm.assert_frame_equal(result, expected)
 

pandas/tests/io/parser/common/test_index.py

@@ -258,10 +258,10 @@ def test_read_csv_no_index_name(all_parsers, csv_dir_path):
                 datetime(2000, 1, 5),
                 datetime(2000, 1, 6),
                 datetime(2000, 1, 7),
-            ]
+            ],
+            dtype="M8[s]",
         ),
     )
-    expected.index = expected.index.as_unit("s")
     tm.assert_frame_equal(result, expected)
 
 

pandas/tests/io/parser/test_parse_dates.py

@@ -469,8 +469,9 @@ def test_date_col_as_index_col(all_parsers):
             datetime(1999, 1, 27, 21, 0),
             datetime(1999, 1, 27, 22, 0),
         ],
+        dtype="M8[s]",
         name="X1",
-    ).as_unit("s")
+    )
     expected = DataFrame(
         [
             ["KORD", " 18:56:00", 0.81, 2.81, 7.2, 0.0, 280.0],
@@ -738,8 +739,8 @@ def test_date_parser_int_bug(all_parsers):
         ),
         raise_on_extra_warnings=False,
     )
-    dti = Index([Timestamp("2012-07-24 04:12:30")], name="posix_timestamp").as_unit(
-        "us"
+    dti = Index(
+        [Timestamp("2012-07-24 04:12:30")], dtype="M8[us]", name="posix_timestamp"
     )
     expected = DataFrame(
         [
@@ -1774,7 +1775,6 @@ def test_parse_timezone(all_parsers):
         tz=timezone(timedelta(minutes=540)),
         unit="s",
     )._with_freq(None)
-
     expected_data = {"dt": dti, "val": [23350, 23400, 23400, 23400, 23400]}
 
     expected = DataFrame(expected_data)

pandas/tests/io/parser/test_read_fwf.py

@@ -310,8 +310,9 @@ def test_fwf_regression():
                 "2009-06-13 20:40:00",
                 "2009-06-13 20:50:00",
                 "2009-06-13 21:00:00",
-            ]
-        ).as_unit("us"),
+            ],
+            dtype="M8[us]",
+        ),
         columns=["SST", "T010", "T020", "T030", "T060", "T080", "T100"],
     )
     tm.assert_frame_equal(result, expected)

pandas/tests/io/parser/test_skiprows.py

@@ -42,8 +42,10 @@ def test_skip_rows_bug(all_parsers, skiprows):
         StringIO(text), skiprows=skiprows, header=None, index_col=0, parse_dates=True
     )
     index = Index(
-        [datetime(2000, 1, 1), datetime(2000, 1, 2), datetime(2000, 1, 3)], name=0
-    ).as_unit("s")
+        [datetime(2000, 1, 1), datetime(2000, 1, 2), datetime(2000, 1, 3)],
+        dtype="M8[s]",
+        name=0,
+    )
 
     expected = DataFrame(
         np.arange(1.0, 10.0).reshape((3, 3)), columns=[1, 2, 3], index=index
@@ -85,8 +87,10 @@ def test_skip_rows_blank(all_parsers):
         StringIO(text), skiprows=6, header=None, index_col=0, parse_dates=True
     )
     index = Index(
-        [datetime(2000, 1, 1), datetime(2000, 1, 2), datetime(2000, 1, 3)], name=0
-    ).as_unit("s")
+        [datetime(2000, 1, 1), datetime(2000, 1, 2), datetime(2000, 1, 3)],
+        dtype="M8[s]",
+        name=0,
+    )
 
     expected = DataFrame(
         np.arange(1.0, 10.0).reshape((3, 3)), columns=[1, 2, 3], index=index

pandas/tests/scalar/test_nat.py

@@ -440,11 +440,9 @@ def test_nat_rfloordiv_timedelta(val, expected):
 @pytest.mark.parametrize(
     "value",
     [
-        DatetimeIndex(["2011-01-01", "2011-01-02"], name="x").as_unit("ns"),
-        DatetimeIndex(["2011-01-01", "2011-01-02"], tz="US/Eastern", name="x").as_unit(
-            "ns"
-        ),
-        DatetimeArray._from_sequence(["2011-01-01", "2011-01-02"]).as_unit("ns"),
+        DatetimeIndex(["2011-01-01", "2011-01-02"], name="x"),
+        DatetimeIndex(["2011-01-01", "2011-01-02"], tz="US/Eastern", name="x"),
+        DatetimeArray._from_sequence(["2011-01-01", "2011-01-02"]),
         DatetimeArray._from_sequence(
             ["2011-01-01", "2011-01-02"], dtype=DatetimeTZDtype(tz="US/Pacific")
         ),

pandas/tests/series/accessors/test_dt_accessor.py

@@ -383,7 +383,7 @@ def test_dt_round_tz_nonexistent(self, method, ts_str, freq):
         tm.assert_series_equal(result, expected)
 
         result = getattr(ser.dt, method)(freq, nonexistent="NaT")
-        expected = Series([pd.NaT], dtype="M8[s]").dt.tz_localize(result.dt.tz)
+        expected = Series([pd.NaT]).dt.tz_localize(result.dt.tz)
         tm.assert_series_equal(result, expected)
 
         with pytest.raises(pytz.NonExistentTimeError, match="2018-03-11 02:00:00"):

pandas/tests/tseries/offsets/test_offsets.py

@@ -504,7 +504,7 @@ def test_add_empty_datetimeindex(self, offset_types, tz_naive_fixture):
         # GH#12724, GH#30336
         offset_s = _create_offset(offset_types)
 
-        dti = DatetimeIndex([], tz=tz_naive_fixture)
+        dti = DatetimeIndex([], tz=tz_naive_fixture).as_unit("ns")
 
         warn = None
         if isinstance(