fix _can_hold_na case

Author: topper-123

pandas/core/indexes/base.py

@@ -9,7 +9,6 @@
     FrozenSet,
     Hashable,
     List,
-    NewType,
     Optional,
     Sequence,
     Tuple,
@@ -24,13 +23,16 @@
 from pandas._libs import algos as libalgos, index as libindex, lib
 import pandas._libs.join as libjoin
 from pandas._libs.lib import is_datetime_array, no_default
-from pandas._libs.tslibs import IncompatibleFrequency, OutOfBoundsDatetime, Timestamp
+from pandas._libs.tslibs import OutOfBoundsDatetime, Timestamp
+from pandas._libs.tslibs.period import IncompatibleFrequency
 from pandas._libs.tslibs.timezones import tz_compare
 from pandas._typing import AnyArrayLike, Dtype, DtypeObj, Label
+from pandas.compat import set_function_name
 from pandas.compat.numpy import function as nv
 from pandas.errors import DuplicateLabelError, InvalidIndexError
 from pandas.util._decorators import Appender, cache_readonly, doc
 
+from pandas.core.dtypes import concat as _concat
 from pandas.core.dtypes.cast import (
     maybe_cast_to_integer_array,
     validate_numeric_casting,
@@ -66,6 +68,7 @@
 from pandas.core.dtypes.concat import concat_compat
 from pandas.core.dtypes.generic import (
     ABCCategorical,
+    ABCDataFrame,
     ABCDatetimeIndex,
     ABCMultiIndex,
     ABCPandasArray,
@@ -76,7 +79,7 @@
 )
 from pandas.core.dtypes.missing import array_equivalent, isna
 
-from pandas.core import missing, ops
+from pandas.core import ops
 from pandas.core.accessor import CachedAccessor
 import pandas.core.algorithms as algos
 from pandas.core.arrays import Categorical, ExtensionArray
@@ -85,6 +88,7 @@
 import pandas.core.common as com
 from pandas.core.indexers import deprecate_ndim_indexing
 from pandas.core.indexes.frozen import FrozenList
+import pandas.core.missing as missing
 from pandas.core.ops import get_op_result_name
 from pandas.core.ops.invalid import make_invalid_op
 from pandas.core.sorting import ensure_key_mapped, nargsort
@@ -118,10 +122,24 @@
 str_t = str
 
 
-_o_dtype = np.dtype(object)
+def _make_arithmetic_op(op, cls):
+    def index_arithmetic_method(self, other):
+        if isinstance(other, (ABCSeries, ABCDataFrame, ABCTimedeltaIndex)):
+            return NotImplemented
+
+        from pandas import Series
+
+        result = op(Series(self), other)
+        if isinstance(result, tuple):
+            return (Index(result[0]), Index(result[1]))
+        return Index(result)
 
+    name = f"__{op.__name__}__"
+    return set_function_name(index_arithmetic_method, name, cls)
 
-_Identity = NewType("_Identity", object)
+
+_o_dtype = np.dtype(object)
+_Identity = object
 
 
 def _new_Index(cls, d):
@@ -220,7 +238,7 @@ def _outer_indexer(self, left, right):
 
     _typ = "index"
     _data: Union[ExtensionArray, np.ndarray]
-    _id: _Identity
+    _id = None
     _name: Label = None
     # MultiIndex.levels previously allowed setting the index name. We
     # don't allow this anymore, and raise if it happens rather than
@@ -435,9 +453,8 @@ def _simple_new(cls, values, name: Label = None):
         result._index_data = values
         result._name = name
         result._cache = {}
-        result._reset_identity()
 
-        return result
+        return result._reset_identity()
 
     @cache_readonly
     def _constructor(self):
@@ -541,16 +558,15 @@ def is_(self, other) -> bool:
         --------
         Index.identical : Works like ``Index.is_`` but also checks metadata.
         """
-        try:
-            return self._id is other._id
-        except AttributeError:
-            return False
+        # use something other than None to be clearer
+        return self._id is getattr(other, "_id", Ellipsis) and self._id is not None
 
-    def _reset_identity(self) -> None:
+    def _reset_identity(self):
         """
         Initializes or resets ``_id`` attribute with new object.
         """
-        self._id = _Identity(object())
+        self._id = _Identity()
+        return self
 
     def _cleanup(self):
         self._engine.clear_mapping()
@@ -4207,7 +4223,7 @@ def _concat(self, to_concat, name):
         """
         to_concat = [x._values if isinstance(x, Index) else x for x in to_concat]
 
-        result = concat_compat(to_concat)
+        result = _concat.concat_compat(to_concat)
         return Index(result, name=name)
 
     def putmask(self, mask, value):
@@ -5363,12 +5379,22 @@ def _cmp_method(self, other, op):
         """
         Wrapper used to dispatch comparison operations.
         """
-        if self.is_(other):
+        from .multi import MultiIndex
+
+        if self.is_(other) and not isinstance(self, MultiIndex):
             # short-circuit when other is same as self
-            if op in (operator.eq, operator.le, operator.ge):
-                return np.ones(self.shape, dtype=bool)
-            elif op in (operator.ne, operator.lt, operator.gt):
-                return np.zeros(self.shape, dtype=bool)
+            bool_arr_type, na_bool = {
+                operator.eq: (np.ones, False),
+                operator.le: (np.ones, False),
+                operator.ge: (np.ones, False),
+                operator.ne: (np.zeros, True),
+                operator.lt: (np.zeros, True),
+                operator.gt: (np.zeros, True),
+            }[op]
+            bool_arr = bool_arr_type(self.shape, dtype=bool)
+            if self._can_hold_na:
+                bool_arr[isna(self)] = na_bool
+            return bool_arr
 
         if isinstance(other, (np.ndarray, Index, ABCSeries, ExtensionArray)):
             if len(self) != len(other):