DEPR: enforce deprecation of unitless td64/dt64 (#30199)

Author: jbrockmendel

pandas/_libs/tslibs/timedeltas.pyx

@@ -1460,7 +1460,7 @@ class Timedelta(_Timedelta):
                 # also timedelta-like
                 return _broadcast_floordiv_td64(self.value, other, _rfloordiv)
 
-            # Includes integer array // Timedelta, deprecated in GH#19761
+            # Includes integer array // Timedelta, disallowed in GH#19761
             raise TypeError(f'Invalid dtype {other.dtype} for __floordiv__')
 
         elif is_float_object(other) and util.is_nan(other):

pandas/core/arrays/datetimes.py

@@ -1,5 +1,4 @@
 from datetime import datetime, time, timedelta
-import textwrap
 from typing import Union
 import warnings
 
@@ -2109,15 +2108,13 @@ def _validate_dt64_dtype(dtype):
     if dtype is not None:
         dtype = pandas_dtype(dtype)
         if is_dtype_equal(dtype, np.dtype("M8")):
-            # no precision, warn
+            # no precision, disallowed GH#24806
             dtype = _NS_DTYPE
-            msg = textwrap.dedent(
-                """\
-                Passing in 'datetime64' dtype with no precision is deprecated
-                and will raise in a future version. Please pass in
-                'datetime64[ns]' instead."""
+            msg = (
+                "Passing in 'datetime64' dtype with no precision is not allowed. "
+                "Please pass in 'datetime64[ns]' instead."
             )
-            warnings.warn(msg, FutureWarning, stacklevel=5)
+            raise ValueError(msg)
 
         if (isinstance(dtype, np.dtype) and dtype != _NS_DTYPE) or not isinstance(
             dtype, (np.dtype, DatetimeTZDtype)

pandas/core/arrays/timedeltas.py

@@ -1,7 +1,5 @@
 from datetime import timedelta
-import textwrap
 from typing import List
-import warnings
 
 import numpy as np
 
@@ -1123,14 +1121,13 @@ def objects_to_td64ns(data, unit="ns", errors="raise"):
 def _validate_td64_dtype(dtype):
     dtype = pandas_dtype(dtype)
     if is_dtype_equal(dtype, np.dtype("timedelta64")):
+        # no precision disallowed GH#24806
         dtype = _TD_DTYPE
-        msg = textwrap.dedent(
-            """\
-            Passing in 'timedelta' dtype with no precision is deprecated
-            and will raise in a future version. Please pass in
-            'timedelta64[ns]' instead."""
+        msg = (
+            "Passing in 'timedelta' dtype with no precision is not allowed. "
+            "Please pass in 'timedelta64[ns]' instead."
         )
-        warnings.warn(msg, FutureWarning, stacklevel=4)
+        raise ValueError(msg)
 
     if not is_dtype_equal(dtype, _TD_DTYPE):
         raise ValueError(_BAD_DTYPE.format(dtype=dtype))

pandas/io/pytables.py

@@ -176,15 +176,6 @@ class DuplicateWarning(Warning):
 # formats
 _FORMAT_MAP = {"f": "fixed", "fixed": "fixed", "t": "table", "table": "table"}
 
-format_deprecate_doc = """
-the table keyword has been deprecated
-use the format='fixed(f)|table(t)' keyword instead
-  fixed(f) : specifies the Fixed format
-             and is the default for put operations
-  table(t) : specifies the Table format
-             and is the default for append operations
-"""
-
 # storer class map
 _STORER_MAP = {
     "series": "SeriesFixed",

pandas/tests/indexes/datetimes/test_construction.py

@@ -774,18 +774,15 @@ def test_construction_with_nat_and_tzlocal(self):
         expected = DatetimeIndex([Timestamp("2018", tz=tz), pd.NaT])
         tm.assert_index_equal(result, expected)
 
-    def test_constructor_no_precision_warns(self):
+    def test_constructor_no_precision_raises(self):
         # GH-24753, GH-24739
-        expected = pd.DatetimeIndex(["2000"], dtype="datetime64[ns]")
 
-        # we set the stacklevel for DatetimeIndex
-        with tm.assert_produces_warning(FutureWarning):
-            result = pd.DatetimeIndex(["2000"], dtype="datetime64")
-        tm.assert_index_equal(result, expected)
+        msg = "with no precision is not allowed"
+        with pytest.raises(ValueError, match=msg):
+            pd.DatetimeIndex(["2000"], dtype="datetime64")
 
-        with tm.assert_produces_warning(FutureWarning, check_stacklevel=False):
-            result = pd.Index(["2000"], dtype="datetime64")
-        tm.assert_index_equal(result, expected)
+        with pytest.raises(ValueError, match=msg):
+            pd.Index(["2000"], dtype="datetime64")
 
     def test_constructor_wrong_precision_raises(self):
         with pytest.raises(ValueError):

pandas/tests/indexes/timedeltas/test_construction.py

@@ -197,18 +197,15 @@ def test_constructor_name(self):
         idx2 = TimedeltaIndex(idx, name="something else")
         assert idx2.name == "something else"
 
-    def test_constructor_no_precision_warns(self):
+    def test_constructor_no_precision_raises(self):
         # GH-24753, GH-24739
-        expected = pd.TimedeltaIndex(["2000"], dtype="timedelta64[ns]")
 
-        # we set the stacklevel for DatetimeIndex
-        with tm.assert_produces_warning(FutureWarning):
-            result = pd.TimedeltaIndex(["2000"], dtype="timedelta64")
-        tm.assert_index_equal(result, expected)
+        msg = "with no precision is not allowed"
+        with pytest.raises(ValueError, match=msg):
+            pd.TimedeltaIndex(["2000"], dtype="timedelta64")
 
-        with tm.assert_produces_warning(FutureWarning, check_stacklevel=False):
-            result = pd.Index(["2000"], dtype="timedelta64")
-        tm.assert_index_equal(result, expected)
+        with pytest.raises(ValueError, match=msg):
+            pd.Index(["2000"], dtype="timedelta64")
 
     def test_constructor_wrong_precision_raises(self):
         with pytest.raises(ValueError):