DEPR: is_int64_dtype

doc/source/whatsnew/v2.1.0.rst

@@ -176,6 +176,7 @@ Deprecations
 - Deprecated making :meth:`Series.apply` return a :class:`DataFrame` when the passed-in callable returns a :class:`Series` object. In the future this will return a :class:`Series` whose values are themselves :class:`Series`. This pattern was very slow and it's recommended to use alternative methods to archive the same goal (:issue:`52116`)
 - Deprecated parameter ``convert_type`` in :meth:`Series.apply` (:issue:`52140`)
 - Deprecated ``freq`` parameter in :class:`PeriodArray` constructor, pass ``dtype`` instead (:issue:`52462`)
+- Deprecated :func:`is_int64_dtype`, check ``dtype == np.dtype(np.int64)`` instead (:issue:`52564`)
 -
 
 .. ---------------------------------------------------------------------------

pandas/conftest.py

@@ -135,6 +135,7 @@ def pytest_collection_modifyitems(items, config) -> None:
     # Warnings from doctests that can be ignored; place reason in comment above.
     # Each entry specifies (path, message) - see the ignore_doctest_warning function
     ignored_doctest_warnings = [
+        ("is_int64_dtype", "is_int64_dtype is deprecated"),
         # Docstring divides by zero to show behavior difference
         ("missing.mask_zero_div_zero", "divide by zero encountered"),
         (

pandas/core/dtypes/common.py

@@ -19,6 +19,7 @@
     lib,
 )
 from pandas._libs.tslibs import conversion
+from pandas.util._exceptions import find_stack_level
 
 from pandas.core.dtypes.base import _registry as registry
 from pandas.core.dtypes.dtypes import (
@@ -847,6 +848,13 @@ def is_int64_dtype(arr_or_dtype) -> bool:
     >>> is_int64_dtype(np.array([1, 2], dtype=np.uint32))  # unsigned
     False
     """
+    # GH#52564
+    warnings.warn(
+        "is_int64_dtype is deprecated and will be removed in a future "
+        "version. Use dtype == np.int64 instead.",
+        FutureWarning,
+        stacklevel=find_stack_level(),
+    )
     return _is_dtype_type(arr_or_dtype, classes(np.int64))
 
 

pandas/tests/dtypes/test_common.py

@@ -169,7 +169,13 @@ def test_get_dtype_error_catch(func):
     #
     # No exception should be raised.
 
-    assert not func(None)
+    msg = f"{func.__name__} is deprecated"
+    warn = None
+    if func is com.is_int64_dtype:
+        warn = FutureWarning
+
+    with tm.assert_produces_warning(warn, match=msg):
+        assert not func(None)
 
 
 def test_is_object():
@@ -407,7 +413,9 @@ def test_is_not_unsigned_integer_dtype(dtype):
     "dtype", [np.int64, np.array([1, 2], dtype=np.int64), "Int64", pd.Int64Dtype]
 )
 def test_is_int64_dtype(dtype):
-    assert com.is_int64_dtype(dtype)
+    msg = "is_int64_dtype is deprecated"
+    with tm.assert_produces_warning(FutureWarning, match=msg):
+        assert com.is_int64_dtype(dtype)
 
 
 def test_type_comparison_with_numeric_ea_dtype(any_numeric_ea_dtype):
@@ -443,7 +451,9 @@ def test_type_comparison_with_signed_int_ea_dtype_and_signed_int_numpy_dtype(
     ],
 )
 def test_is_not_int64_dtype(dtype):
-    assert not com.is_int64_dtype(dtype)
+    msg = "is_int64_dtype is deprecated"
+    with tm.assert_produces_warning(FutureWarning, match=msg):
+        assert not com.is_int64_dtype(dtype)
 
 
 def test_is_datetime64_any_dtype():

pandas/tests/indexes/ranges/test_join.py

@@ -1,7 +1,5 @@
 import numpy as np
 
-from pandas.core.dtypes.common import is_int64_dtype
-
 from pandas import (
     Index,
     RangeIndex,
@@ -31,7 +29,7 @@ def test_join_outer(self):
             dtype=np.intp,
         )
 
-        assert isinstance(res, Index) and is_int64_dtype(res.dtype)
+        assert isinstance(res, Index) and res.dtype == np.dtype(np.int64)
         assert not isinstance(res, RangeIndex)
         tm.assert_index_equal(res, eres, exact=True)
         tm.assert_numpy_array_equal(lidx, elidx)