normalize ref_count usage

Author: jorisvandenbossche

pandas/compat/_constants.py

@@ -18,7 +18,10 @@
 PYPY = platform.python_implementation() == "PyPy"
 WASM = (sys.platform == "emscripten") or (platform.machine() in ["wasm32", "wasm64"])
 ISMUSL = "musl" in (sysconfig.get_config_var("HOST_GNU_TYPE") or "")
-REF_COUNT = 3 if PY314 else 2
+# the refcount for self in a chained __setitem__/.(i)loc indexing/method call
+REF_COUNT = 2 if PY314 else 3
+REF_COUNT_IDX = 2
+REF_COUNT_METHOD = 1 if PY314 else 2
 CHAINED_WARNING_DISABLED = PYPY
 
 

pandas/core/frame.py

@@ -52,6 +52,7 @@
 from pandas.compat import CHAINED_WARNING_DISABLED
 from pandas.compat._constants import (
     REF_COUNT,
+    REF_COUNT_METHOD,
 )
 from pandas.compat._optional import import_optional_dependency
 from pandas.compat.numpy import function as nv
@@ -9365,9 +9366,9 @@ def update(
         2  3    6.0
         """
         if not CHAINED_WARNING_DISABLED:
-            if sys.getrefcount(self) < REF_COUNT and not lib.is_local_in_caller_frame(
+            if sys.getrefcount(
                 self
-            ):
+            ) <= REF_COUNT_METHOD and not lib.is_local_in_caller_frame(self):
                 warnings.warn(
                     _chained_assignment_method_msg,
                     ChainedAssignmentError,

pandas/core/generic.py

@@ -84,7 +84,7 @@
 )
 from pandas.compat import CHAINED_WARNING_DISABLED
 from pandas.compat._constants import (
-    REF_COUNT,
+    REF_COUNT_METHOD,
 )
 from pandas.compat._optional import import_optional_dependency
 from pandas.compat.numpy import function as nv
@@ -7084,7 +7084,7 @@ def fillna(
             if not CHAINED_WARNING_DISABLED:
                 if sys.getrefcount(
                     self
-                ) < REF_COUNT and not lib.is_local_in_caller_frame(self):
+                ) <= REF_COUNT_METHOD and not lib.is_local_in_caller_frame(self):
                     warnings.warn(
                         _chained_assignment_method_msg,
                         ChainedAssignmentError,
@@ -7333,7 +7333,7 @@ def ffill(
             if not CHAINED_WARNING_DISABLED:
                 if sys.getrefcount(
                     self
-                ) < REF_COUNT and not lib.is_local_in_caller_frame(self):
+                ) <= REF_COUNT_METHOD and not lib.is_local_in_caller_frame(self):
                     warnings.warn(
                         _chained_assignment_method_msg,
                         ChainedAssignmentError,
@@ -7475,7 +7475,7 @@ def bfill(
             if not CHAINED_WARNING_DISABLED:
                 if sys.getrefcount(
                     self
-                ) < REF_COUNT and not lib.is_local_in_caller_frame(self):
+                ) <= REF_COUNT_METHOD and not lib.is_local_in_caller_frame(self):
                     warnings.warn(
                         _chained_assignment_method_msg,
                         ChainedAssignmentError,
@@ -7562,7 +7562,7 @@ def replace(
             if not CHAINED_WARNING_DISABLED:
                 if sys.getrefcount(
                     self
-                ) < REF_COUNT and not lib.is_local_in_caller_frame(self):
+                ) <= REF_COUNT_METHOD and not lib.is_local_in_caller_frame(self):
                     warnings.warn(
                         _chained_assignment_method_msg,
                         ChainedAssignmentError,
@@ -7927,7 +7927,7 @@ def interpolate(
             if not CHAINED_WARNING_DISABLED:
                 if sys.getrefcount(
                     self
-                ) < REF_COUNT and not lib.is_local_in_caller_frame(self):
+                ) <= REF_COUNT_METHOD and not lib.is_local_in_caller_frame(self):
                     warnings.warn(
                         _chained_assignment_method_msg,
                         ChainedAssignmentError,
@@ -8584,7 +8584,7 @@ def clip(
             if not CHAINED_WARNING_DISABLED:
                 if sys.getrefcount(
                     self
-                ) < REF_COUNT and not lib.is_local_in_caller_frame(self):
+                ) <= REF_COUNT_METHOD and not lib.is_local_in_caller_frame(self):
                     warnings.warn(
                         _chained_assignment_method_msg,
                         ChainedAssignmentError,
@@ -10221,7 +10221,7 @@ def where(
             if not CHAINED_WARNING_DISABLED:
                 if sys.getrefcount(
                     self
-                ) < REF_COUNT and not lib.is_local_in_caller_frame(self):
+                ) <= REF_COUNT_METHOD and not lib.is_local_in_caller_frame(self):
                     warnings.warn(
                         _chained_assignment_method_msg,
                         ChainedAssignmentError,
@@ -10287,7 +10287,7 @@ def mask(
             if not CHAINED_WARNING_DISABLED:
                 if sys.getrefcount(
                     self
-                ) < REF_COUNT and not lib.is_local_in_caller_frame(self):
+                ) <= REF_COUNT_METHOD and not lib.is_local_in_caller_frame(self):
                     warnings.warn(
                         _chained_assignment_method_msg,
                         ChainedAssignmentError,

pandas/core/indexing.py

@@ -16,7 +16,7 @@
 from pandas._libs.indexing import NDFrameIndexerBase
 from pandas._libs.lib import item_from_zerodim
 from pandas.compat import CHAINED_WARNING_DISABLED
-from pandas.compat._constants import REF_COUNT
+from pandas.compat._constants import REF_COUNT_IDX
 from pandas.errors import (
     AbstractMethodError,
     ChainedAssignmentError,
@@ -918,7 +918,7 @@ def _ensure_listlike_indexer(self, key, axis=None, value=None) -> None:
     @final
     def __setitem__(self, key, value) -> None:
         if not CHAINED_WARNING_DISABLED:
-            if sys.getrefcount(self.obj) <= REF_COUNT:
+            if sys.getrefcount(self.obj) <= REF_COUNT_IDX:
                 warnings.warn(
                     _chained_assignment_msg, ChainedAssignmentError, stacklevel=2
                 )
@@ -2586,7 +2586,7 @@ def __getitem__(self, key):
 
     def __setitem__(self, key, value) -> None:
         if not CHAINED_WARNING_DISABLED:
-            if sys.getrefcount(self.obj) <= REF_COUNT:
+            if sys.getrefcount(self.obj) <= REF_COUNT_IDX:
                 warnings.warn(
                     _chained_assignment_msg, ChainedAssignmentError, stacklevel=2
                 )
@@ -2617,7 +2617,7 @@ def _convert_key(self, key):
 
     def __setitem__(self, key, value) -> None:
         if not CHAINED_WARNING_DISABLED:
-            if sys.getrefcount(self.obj) <= REF_COUNT:
+            if sys.getrefcount(self.obj) <= REF_COUNT_IDX:
                 warnings.warn(
                     _chained_assignment_msg, ChainedAssignmentError, stacklevel=2
                 )

pandas/core/series.py

@@ -37,6 +37,7 @@
 from pandas.compat import CHAINED_WARNING_DISABLED
 from pandas.compat._constants import (
     REF_COUNT,
+    REF_COUNT_METHOD,
 )
 from pandas.compat._optional import import_optional_dependency
 from pandas.compat.numpy import function as nv
@@ -3354,9 +3355,9 @@ def update(self, other: Series | Sequence | Mapping) -> None:
         dtype: int64
         """
         if not CHAINED_WARNING_DISABLED:
-            if sys.getrefcount(self) < REF_COUNT and not lib.is_local_in_caller_frame(
+            if sys.getrefcount(
                 self
-            ):
+            ) <= REF_COUNT_METHOD and not lib.is_local_in_caller_frame(self):
                 warnings.warn(
                     _chained_assignment_method_msg,
                     ChainedAssignmentError,