From 7693aea2ae5bd18390d1c12529bc9021a48fd047 Mon Sep 17 00:00:00 2001
From: Brock <jbrockmendel@gmail.com>
Date: Wed, 27 Jan 2021 17:32:50 -0800
Subject: [PATCH 1/2] REF: shallow_copy->simple_new/rename

---
 pandas/core/indexes/base.py  | 14 +++++++++-----
 pandas/core/indexes/range.py | 28 ++++++++++++++++++++++++++--
 2 files changed, 35 insertions(+), 7 deletions(-)

diff --git a/pandas/core/indexes/base.py b/pandas/core/indexes/base.py
index 40215ea87f978..d00635b4d1551 100644
--- a/pandas/core/indexes/base.py
+++ b/pandas/core/indexes/base.py
@@ -824,7 +824,7 @@ def take(self, indices, axis=0, allow_fill=True, fill_value=None, **kwargs):
         taken = algos.take(
             self._values, indices, allow_fill=allow_fill, fill_value=self._na_value
         )
-        return self._shallow_copy(taken)
+        return type(self)._simple_new(taken, name=self.name)
 
     @final
     def _maybe_disallow_fill(self, allow_fill: bool, fill_value, indices) -> bool:
@@ -892,7 +892,9 @@ def _maybe_disallow_fill(self, allow_fill: bool, fill_value, indices) -> bool:
     def repeat(self, repeats, axis=None):
         repeats = ensure_platform_int(repeats)
         nv.validate_repeat((), {"axis": axis})
-        return self._shallow_copy(self._values.repeat(repeats))
+        res_values = self._values.repeat(repeats)
+
+        return type(self)._simple_new(res_values, name=self.name)
 
     # --------------------------------------------------------------------
     # Copying Methods
@@ -2462,7 +2464,8 @@ def dropna(self, how="any"):
             raise ValueError(f"invalid how option: {how}")
 
         if self.hasnans:
-            return self._shallow_copy(self._values[~self._isnan])
+            res_values = self._values[~self._isnan]
+            return type(self)._simple_new(res_values, name=self.name)
         return self._shallow_copy()
 
     # --------------------------------------------------------------------
@@ -4553,7 +4556,7 @@ def putmask(self, mask, value):
             return self.astype(object).putmask(mask, value)
 
         np.putmask(values, mask, converted)
-        return self._shallow_copy(values)
+        return type(self)._simple_new(values, name=self.name)
 
     def equals(self, other: Any) -> bool:
         """
@@ -5715,7 +5718,8 @@ def delete(self, loc):
         >>> idx.delete([0, 2])
         Index(['b'], dtype='object')
         """
-        return self._shallow_copy(np.delete(self._data, loc))
+        res_values = np.delete(self._data, loc)
+        return type(self)._simple_new(res_values, name=self.name)
 
     def insert(self, loc: int, item):
         """
diff --git a/pandas/core/indexes/range.py b/pandas/core/indexes/range.py
index fbc7f578d760e..6453f66815f27 100644
--- a/pandas/core/indexes/range.py
+++ b/pandas/core/indexes/range.py
@@ -13,6 +13,7 @@
 from pandas._typing import Dtype
 from pandas.compat.numpy import function as nv
 from pandas.util._decorators import cache_readonly, doc
+from pandas.util._exceptions import rewrite_exception
 
 from pandas.core.dtypes.common import (
     ensure_platform_int,
@@ -169,9 +170,16 @@ def _data(self):
         return np.arange(self.start, self.stop, self.step, dtype=np.int64)
 
     @cache_readonly
-    def _int64index(self) -> Int64Index:
+    def __int64index(self) -> Int64Index:
         return Int64Index._simple_new(self._data, name=self.name)
 
+    @property
+    def _int64index(self):
+        # wrap __int64index so we can be sure its name matches self.name
+        res = self.__int64index
+        res._name = self._name
+        return res
+
     def _get_data_as_items(self):
         """ return a list of tuples of start, stop, step """
         rng = self._range
@@ -390,6 +398,22 @@ def _get_indexer(self, target, method=None, limit=None, tolerance=None):
 
     # --------------------------------------------------------------------
 
+    def repeat(self, repeats, axis=None):
+        return self._int64index.repeat(repeats, axis=axis)
+
+    def delete(self, loc):
+        return self._int64index.delete(loc)
+
+    def take(self, indices, axis=0, allow_fill=True, fill_value=None, **kwargs):
+        with rewrite_exception("Int64Index", type(self).__name__):
+            return self._int64index.take(
+                indices,
+                axis=axis,
+                allow_fill=allow_fill,
+                fill_value=fill_value,
+                **kwargs,
+            )
+
     def tolist(self):
         return list(self._range)
 
@@ -645,7 +669,7 @@ def _difference(self, other, sort=None):
             overlap = overlap[::-1]
 
         if len(overlap) == 0:
-            return self._shallow_copy(name=res_name)
+            return self.rename(name=res_name)
         if len(overlap) == len(self):
             return self[:0].rename(res_name)
         if not isinstance(overlap, RangeIndex):

From 82d00446864610bda87862a9c9479f4c5cb7e036 Mon Sep 17 00:00:00 2001
From: Brock <jbrockmendel@gmail.com>
Date: Wed, 27 Jan 2021 18:49:17 -0800
Subject: [PATCH 2/2] __int64index -> _cached_int64index

---
 pandas/core/indexes/range.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/pandas/core/indexes/range.py b/pandas/core/indexes/range.py
index 6453f66815f27..f65102dbaa611 100644
--- a/pandas/core/indexes/range.py
+++ b/pandas/core/indexes/range.py
@@ -170,13 +170,13 @@ def _data(self):
         return np.arange(self.start, self.stop, self.step, dtype=np.int64)
 
     @cache_readonly
-    def __int64index(self) -> Int64Index:
+    def _cached_int64index(self) -> Int64Index:
         return Int64Index._simple_new(self._data, name=self.name)
 
     @property
     def _int64index(self):
-        # wrap __int64index so we can be sure its name matches self.name
-        res = self.__int64index
+        # wrap _cached_int64index so we can be sure its name matches self.name
+        res = self._cached_int64index
         res._name = self._name
         return res