DEPR: deprecate Index.is_integer (#50178)

doc/source/whatsnew/v2.0.0.rst

@@ -569,8 +569,7 @@ Deprecations
 ~~~~~~~~~~~~
 - Deprecated argument ``infer_datetime_format`` in :func:`to_datetime` and :func:`read_csv`, as a strict version of it is now the default (:issue:`48621`)
 - Deprecated :func:`pandas.io.sql.execute`(:issue:`50185`)
--
-
+- :meth:`Index.is_integer` has been deprecated. Use :func:`pandas.api.types.is_integer_dtype` instead (:issue:`50042`)
 - :meth:`Index.is_floating` has been deprecated. Use :func:`pandas.api.types.is_float_dtype` instead (:issue:`50042`)
 
 .. ---------------------------------------------------------------------------

pandas/_testing/asserters.py

@@ -15,6 +15,7 @@
     is_bool,
     is_categorical_dtype,
     is_extension_array_dtype,
+    is_integer_dtype,
     is_interval_dtype,
     is_number,
     is_numeric_dtype,
@@ -1335,7 +1336,7 @@ def assert_indexing_slices_equivalent(ser: Series, l_slc: slice, i_slc: slice) -
 
     assert_series_equal(ser.loc[l_slc], expected)
 
-    if not ser.index.is_integer():
+    if not is_integer_dtype(ser.index):
         # For integer indices, .loc and plain getitem are position-based.
         assert_series_equal(ser[l_slc], expected)
 

pandas/core/indexes/base.py

@@ -98,6 +98,7 @@
     is_float_dtype,
     is_hashable,
     is_integer,
+    is_integer_dtype,
     is_interval_dtype,
     is_iterator,
     is_list_like,
@@ -2188,7 +2189,7 @@ def is_boolean(self) -> bool:
 
         See Also
         --------
-        is_integer : Check if the Index only consists of integers.
+        is_integer : Check if the Index only consists of integers (deprecated).
         is_floating : Check if the Index is a floating type (deprecated).
         is_numeric : Check if the Index only consists of numeric data.
         is_object : Check if the Index is of the object dtype.
@@ -2216,6 +2217,9 @@ def is_integer(self) -> bool:
         """
         Check if the Index only consists of integers.
 
+        .. deprecated:: 2.0.0
+            Use `pandas.api.types.is_integer_dtype` instead.
+
         Returns
         -------
         bool
@@ -2244,6 +2248,12 @@ def is_integer(self) -> bool:
         >>> idx.is_integer()
         False
         """
+        warnings.warn(
+            f"{type(self).__name__}.is_integer is deprecated. "
+            "Use pandas.api.types.is_integer_dtype instead.",
+            FutureWarning,
+            stacklevel=find_stack_level(),
+        )
         return self.inferred_type in ["integer"]
 
     @final
@@ -2266,7 +2276,7 @@ def is_floating(self) -> bool:
         See Also
         --------
         is_boolean : Check if the Index only consists of booleans.
-        is_integer : Check if the Index only consists of integers.
+        is_integer : Check if the Index only consists of integers (deprecated).
         is_numeric : Check if the Index only consists of numeric data.
         is_object : Check if the Index is of the object dtype.
         is_categorical : Check if the Index holds categorical data.
@@ -2311,7 +2321,7 @@ def is_numeric(self) -> bool:
         See Also
         --------
         is_boolean : Check if the Index only consists of booleans.
-        is_integer : Check if the Index only consists of integers.
+        is_integer : Check if the Index only consists of integers (deprecated).
         is_floating : Check if the Index is a floating type (deprecated).
         is_object : Check if the Index is of the object dtype.
         is_categorical : Check if the Index holds categorical data.
@@ -2354,7 +2364,7 @@ def is_object(self) -> bool:
         See Also
         --------
         is_boolean : Check if the Index only consists of booleans.
-        is_integer : Check if the Index only consists of integers.
+        is_integer : Check if the Index only consists of integers (deprecated).
         is_floating : Check if the Index is a floating type (deprecated).
         is_numeric : Check if the Index only consists of numeric data.
         is_categorical : Check if the Index holds categorical data.
@@ -2395,7 +2405,7 @@ def is_categorical(self) -> bool:
         --------
         CategoricalIndex : Index for categorical data.
         is_boolean : Check if the Index only consists of booleans.
-        is_integer : Check if the Index only consists of integers.
+        is_integer : Check if the Index only consists of integers (deprecated).
         is_floating : Check if the Index is a floating type (deprecated).
         is_numeric : Check if the Index only consists of numeric data.
         is_object : Check if the Index is of the object dtype.
@@ -2438,7 +2448,7 @@ def is_interval(self) -> bool:
         --------
         IntervalIndex : Index for Interval objects.
         is_boolean : Check if the Index only consists of booleans.
-        is_integer : Check if the Index only consists of integers.
+        is_integer : Check if the Index only consists of integers (deprecated).
         is_floating : Check if the Index is a floating type (deprecated).
         is_numeric : Check if the Index only consists of numeric data.
         is_object : Check if the Index is of the object dtype.
@@ -3877,7 +3887,7 @@ def is_int(v):
 
         if kind == "getitem":
             # called from the getitem slicers, validate that we are in fact integers
-            if self.is_integer() or is_index_slice:
+            if is_integer_dtype(self.dtype) or is_index_slice:
                 # Note: these checks are redundant if we know is_index_slice
                 self._validate_indexer("slice", key.start, "getitem")
                 self._validate_indexer("slice", key.stop, "getitem")

pandas/tests/indexes/common.py

@@ -803,6 +803,12 @@ def test_is_floating_is_deprecated(self, simple_index):
         with tm.assert_produces_warning(FutureWarning):
             idx.is_floating()
 
+    def test_is_integer_is_deprecated(self, simple_index):
+        # GH50042
+        idx = simple_index
+        with tm.assert_produces_warning(FutureWarning):
+            idx.is_integer()
+
 
 class NumericBase(Base):
     """

pandas/tests/indexing/test_indexing.py

@@ -603,7 +603,7 @@ def test_index_type_coercion(self, indexer):
         # integer indexes
         for s in [Series(range(5)), Series(range(5), index=range(1, 6))]:
 
-            assert s.index.is_integer()
+            assert is_integer_dtype(s.index)
 
             s2 = s.copy()
             indexer(s2)[0.1] = 0