API: partial revert of returning read-only EAs from .array/.values

Author: jorisvandenbossche

pandas/core/indexes/base.py

@@ -5023,8 +5023,8 @@ def array(self) -> ExtensionArray:
             from pandas.core.arrays.numpy_ import NumpyExtensionArray
 
             array = NumpyExtensionArray(array)
-        array = array.view()
-        array._readonly = True
+        # array = array.view()
+        # array._readonly = True
         return array
 
     @property

pandas/core/internals/blocks.py

@@ -2387,7 +2387,8 @@ def external_values(values: ArrayLike) -> ArrayLike:
         values.flags.writeable = False
     else:
         # ExtensionArrays
-        values = values.view()
-        values._readonly = True
+        # values = values.view()
+        # values._readonly = True
+        pass
 
     return values

pandas/core/series.py

@@ -819,8 +819,8 @@ def _references(self) -> BlockValuesRefs:
     @property
     def array(self) -> ExtensionArray:
         arr = self._mgr.array_values()
-        arr = arr.view()
-        arr._readonly = True
+        # arr = arr.view()
+        # arr._readonly = True
         return arr
 
     def __len__(self) -> int: