PERF: NDArrayBackedExtensionArray in cython (pandas-dev#40840)

Author: jbrockmendel

pandas/compat/pickle_compat.py

@@ -21,7 +21,6 @@
     PeriodArray,
     TimedeltaArray,
 )
-from pandas.core.internals import BlockManager
 
 if TYPE_CHECKING:
     from pandas import (
@@ -223,8 +222,7 @@ def load_newobj(self):
     elif issubclass(cls, TimedeltaArray) and not args:
         arr = np.array([], dtype="m8[ns]")
         obj = cls.__new__(cls, arr, arr.dtype)
-    elif cls is BlockManager and not args:
-        obj = cls.__new__(cls, (), [], False)
+
     else:
         obj = cls.__new__(cls, *args)
 

pandas/core/arrays/period.py

@@ -178,8 +178,8 @@ class PeriodArray(dtl.DatelikeOps):
         "days_in_month",
         "daysinmonth",
     ]
-    _datetimelike_ops: list[str] = _field_ops + _object_ops + _bool_ops
-    _datetimelike_methods: list[str] = ["strftime", "to_timestamp", "asfreq"]
+    _datetimelike_ops = _field_ops + _object_ops + _bool_ops
+    _datetimelike_methods = ["strftime", "to_timestamp", "asfreq"]
 
     # --------------------------------------------------------------------
     # Constructors