CLN: avoid _ndarray_values, values in MultiIndex (#32452)

Author: jbrockmendel

pandas/core/indexes/multi.py

@@ -18,7 +18,7 @@
 
 from pandas._libs import algos as libalgos, index as libindex, lib
 from pandas._libs.hashtable import duplicated_int64
-from pandas._typing import AnyArrayLike, ArrayLike, Scalar
+from pandas._typing import AnyArrayLike, Scalar
 from pandas.compat.numpy import function as nv
 from pandas.errors import PerformanceWarning, UnsortedIndexError
 from pandas.util._decorators import Appender, cache_readonly
@@ -52,6 +52,7 @@
     ensure_index,
 )
 from pandas.core.indexes.frozen import FrozenList
+from pandas.core.indexes.numeric import Int64Index
 import pandas.core.missing as missing
 from pandas.core.sorting import (
     get_group_index,
@@ -1180,7 +1181,7 @@ def _format_native_types(self, na_rep="nan", **kwargs):
                 sortorder=self.sortorder,
                 verify_integrity=False,
             )
-            return mi.values
+            return mi._values
 
     def format(
         self,
@@ -1419,7 +1420,7 @@ def is_monotonic_increasing(self) -> bool:
         except TypeError:
 
             # we have mixed types and np.lexsort is not happy
-            return Index(self.values).is_monotonic
+            return Index(self._values).is_monotonic
 
     @cache_readonly
     def is_monotonic_decreasing(self) -> bool:
@@ -1612,7 +1613,7 @@ def to_flat_index(self):
                ('bar', 'baz'), ('bar', 'qux')],
               dtype='object')
         """
-        return Index(self.values, tupleize_cols=False)
+        return Index(self._values, tupleize_cols=False)
 
     @property
     def is_all_dates(self) -> bool:
@@ -1914,7 +1915,7 @@ def append(self, other):
                 arrays.append(label.append(appended))
             return MultiIndex.from_arrays(arrays, names=self.names)
 
-        to_concat = (self.values,) + tuple(k._values for k in other)
+        to_concat = (self._values,) + tuple(k._values for k in other)
         new_tuples = np.concatenate(to_concat)
 
         # if all(isinstance(x, MultiIndex) for x in other):
@@ -1924,7 +1925,7 @@ def append(self, other):
             return Index(new_tuples)
 
     def argsort(self, *args, **kwargs) -> np.ndarray:
-        return self.values.argsort(*args, **kwargs)
+        return self._values.argsort(*args, **kwargs)
 
     @Appender(_index_shared_docs["repeat"] % _index_doc_kwargs)
     def repeat(self, repeats, axis=None):
@@ -2368,7 +2369,7 @@ def get_indexer(self, target, method=None, limit=None, tolerance=None):
 
                 # let's instead try with a straight Index
                 if method is None:
-                    return Index(self.values).get_indexer(
+                    return Index(self._values).get_indexer(
                         target, method=method, limit=limit, tolerance=tolerance
                     )
 
@@ -2831,7 +2832,8 @@ def convert_indexer(start, stop, step, indexer=indexer, codes=level_codes):
                 mapper = Series(indexer)
                 indexer = codes.take(ensure_platform_int(indexer))
                 result = Series(Index(indexer).isin(r).nonzero()[0])
-                m = result.map(mapper)._ndarray_values
+                m = result.map(mapper)
+                m = np.asarray(m)
 
             else:
                 m = np.zeros(len(codes), dtype=bool)
@@ -2949,7 +2951,7 @@ def get_locs(self, seq):
         n = len(self)
         indexer = None
 
-        def _convert_to_indexer(r):
+        def _convert_to_indexer(r) -> Int64Index:
             # return an indexer
             if isinstance(r, slice):
                 m = np.zeros(n, dtype=bool)
@@ -3026,13 +3028,16 @@ def _update_indexer(idxr, indexer=indexer):
         if indexer is None:
             return np.array([], dtype=np.int64)
 
+        assert isinstance(indexer, Int64Index), type(indexer)
         indexer = self._reorder_indexer(seq, indexer)
 
-        return indexer._ndarray_values
+        return indexer._values
 
     def _reorder_indexer(
-        self, seq: Tuple[Union[Scalar, Iterable, AnyArrayLike], ...], indexer: ArrayLike
-    ) -> ArrayLike:
+        self,
+        seq: Tuple[Union[Scalar, Iterable, AnyArrayLike], ...],
+        indexer: Int64Index,
+    ) -> Int64Index:
         """
         Reorder an indexer of a MultiIndex (self) so that the label are in the
         same order as given in seq
@@ -3139,8 +3144,8 @@ def equals(self, other) -> bool:
                 if self.nlevels != other.nlevels:
                     return False
 
-            other_vals = com.values_from_object(ensure_index(other))
-            return array_equivalent(self._ndarray_values, other_vals)
+            other_vals = com.values_from_object(other)
+            return array_equivalent(self._values, other_vals)
 
         if self.nlevels != other.nlevels:
             return False
@@ -3232,7 +3237,7 @@ def union(self, other, sort=None):
         # TODO: Index.union returns other when `len(self)` is 0.
 
         uniq_tuples = lib.fast_unique_multiple(
-            [self._ndarray_values, other._ndarray_values], sort=sort
+            [self._values, other._ndarray_values], sort=sort
         )
 
         return MultiIndex.from_arrays(
@@ -3267,7 +3272,7 @@ def intersection(self, other, sort=False):
         if self.equals(other):
             return self
 
-        lvals = self._ndarray_values
+        lvals = self._values
         rvals = other._ndarray_values
 
         uniq_tuples = None  # flag whether _inner_indexer was succesful
@@ -3342,7 +3347,7 @@ def difference(self, other, sort=None):
         indexer = indexer.take((indexer != -1).nonzero()[0])
 
         label_diff = np.setdiff1d(np.arange(this.size), indexer, assume_unique=True)
-        difference = this.values.take(label_diff)
+        difference = this._values.take(label_diff)
         if sort is None:
             difference = sorted(difference)
 
@@ -3359,7 +3364,8 @@ def difference(self, other, sort=None):
     def _convert_can_do_setop(self, other):
         result_names = self.names
 
-        if not hasattr(other, "names"):
+        if not isinstance(other, Index):
+
             if len(other) == 0:
                 other = MultiIndex(
                     levels=[[]] * self.nlevels,
@@ -3456,8 +3462,8 @@ def _wrap_joined_index(self, joined, other):
     @Appender(Index.isin.__doc__)
     def isin(self, values, level=None):
         if level is None:
-            values = MultiIndex.from_tuples(values, names=self.names).values
-            return algos.isin(self.values, values)
+            values = MultiIndex.from_tuples(values, names=self.names)._values
+            return algos.isin(self._values, values)
         else:
             num = self._get_level_number(level)
             levs = self.get_level_values(num)