Rename sentinel value

Author: VeckoTheGecko

src/parcels/_core/fieldset.py

@@ -20,7 +20,7 @@
 from parcels._core.utils.string import _assert_str_and_python_varname
 from parcels._core.utils.time import get_datetime_type_calendar
 from parcels._core.utils.time import is_compatible as datetime_is_compatible
-from parcels._python import _MISSING, _MissingType
+from parcels._python import NOTSET, NotSetType
 from parcels._typing import Mesh
 from parcels.interpolators import (
     XConstantField,
@@ -212,7 +212,7 @@ def from_ugrid_conventions(
         cls,
         ds: ux.UxDataset,
         mesh: str = "spherical",
-        vector_fields: TVectorFieldMapping | None | _MissingType = _MISSING,
+        vector_fields: TVectorFieldMapping | None | NotSetType = NOTSET,
     ):
         """Create a FieldSet from a Parcels compliant uxarray.UxDataset.
 
@@ -250,7 +250,7 @@ def from_sgrid_conventions(
         cls,
         ds: xr.Dataset,
         mesh: Mesh | None = None,
-        vector_fields: TVectorFieldMapping | None | _MissingType = _MISSING,
+        vector_fields: TVectorFieldMapping | None | NotSetType = NOTSET,
     ):  # TODO: Update mesh to be discovered from the dataset metadata
         """Create a FieldSet from a dataset using SGRID convention metadata.
 

src/parcels/_core/model.py

@@ -19,7 +19,7 @@
     assert_all_field_dims_have_axis,  # noqa: F401, leave import for now until decision is made # TODO v4: Make decision
 )
 from parcels._logger import logger
-from parcels._python import _MISSING, _MissingType
+from parcels._python import NOTSET, NotSetType
 from parcels._typing import Mesh
 from parcels.convert import _ds_rename_using_standard_names
 from parcels.interpolators import (
@@ -133,7 +133,7 @@ def construct_fields(self) -> list[Field | VectorField]:
 
     @classmethod
     def from_sgrid_conventions(
-        cls, ds: xr.Dataset, mesh: Mesh | None, vector_fields: TVectorFieldMapping | None | _MissingType
+        cls, ds: xr.Dataset, mesh: Mesh | None, vector_fields: TVectorFieldMapping | None | NotSetType
     ) -> Self:
         ds = ds.copy()
         if mesh is None:
@@ -173,11 +173,11 @@ def from_sgrid_conventions(
 
 
 def resolve_vector_fields(
-    ds: xr.Dataset, vector_fields: TVectorFieldMapping | None | _MissingType
+    ds: xr.Dataset, vector_fields: TVectorFieldMapping | None | NotSetType
 ) -> TVectorFieldMapping:
     if vector_fields is None:
         return {}
-    if vector_fields is _MISSING:  # i.e., the default vectorfield discovery behaviour
+    if vector_fields is NOTSET:  # i.e., the default vectorfield discovery behaviour
         return _default_vector_field_components(ds.data_vars)
     return vector_fields
 
@@ -262,7 +262,7 @@ def scalar_field_names(self) -> list[str]:
 
     @classmethod
     def from_ugrid_conventions(
-        cls, ds: ux.UxDataset, mesh: Mesh, vector_fields: TVectorFieldMapping | None | _MissingType
+        cls, ds: ux.UxDataset, mesh: Mesh, vector_fields: TVectorFieldMapping | None | NotSetType
     ):
         ds_dims = list(ds.dims)
         if not all(dim in ds_dims for dim in ["time", "zf", "zc"]):

src/parcels/_python.py

@@ -7,8 +7,8 @@
 K = TypeVar("K")
 V = TypeVar("V")
 
-_MissingType = enum.Enum("_MissingType", "VALUE")
-_MISSING = _MissingType.VALUE
+NotSetType = enum.Enum("NotSetType", "VALUE")
+NOTSET = NotSetType.VALUE
 
 
 def isinstance_noimport(obj, class_or_tuple):