[KNITRO] Improve type hints

pyomo/contrib/solver/solvers/knitro/api.py

@@ -9,14 +9,12 @@
 #  This software is distributed under the 3-clause BSD License.
 #  ___________________________________________________________________________
 
-from typing import Optional
-
 from pyomo.common.dependencies import attempt_import
 
 knitro, KNITRO_AVAILABLE = attempt_import("knitro")
 
 
-def get_version() -> Optional[str]:
+def get_version() -> str | None:
     if not KNITRO_AVAILABLE:
         return None
     return knitro.__version__

pyomo/contrib/solver/solvers/knitro/base.py

@@ -14,7 +14,6 @@
 import datetime
 import time
 from io import StringIO
-from typing import Optional
 
 from pyomo.common.collections import ComponentMap
 from pyomo.common.errors import ApplicationError, DeveloperError, PyomoException
@@ -56,7 +55,7 @@ class KnitroSolverBase(SolutionProvider, PackageChecker, SolverBase):
     _engine: Engine
     _model_data: KnitroModelData
     _stream: StringIO
-    _saved_var_values: dict[int, Optional[float]]
+    _saved_var_values: dict[int, float | None]
 
     def __init__(self, **kwds) -> None:
         PackageChecker.__init__(self)
@@ -182,10 +181,10 @@ def get_values(
         self,
         item_type: type[ItemType],
         value_type: ValueType,
-        items: Optional[Sequence[ItemType]] = None,
+        items: Sequence[ItemType] | None = None,
         *,
         exists: bool,
-        solution_id: Optional[int] = None,
+        solution_id: int | None = None,
     ) -> Mapping[ItemType, float]:
         error_type = self._get_error_type(item_type, value_type)
         if not exists:

pyomo/contrib/solver/solvers/knitro/callback.py

@@ -10,7 +10,7 @@
 #  ___________________________________________________________________________
 
 from collections.abc import Callable
-from typing import Any, Optional, Protocol
+from typing import Any, Protocol
 
 from pyomo.contrib.solver.solvers.knitro.typing import (
     Callback,
@@ -85,7 +85,7 @@ def hess(self, req: CallbackRequest, res: CallbackResult) -> int:
         return 0
 
 
-def build_callback_handler(function: Function, idx: Optional[int]) -> CallbackHandler:
+def build_callback_handler(function: Function, idx: int | None) -> CallbackHandler:
     if idx is None:
         return ObjectiveCallbackHandler(function)
     return ConstraintCallbackHandler(idx, function)

pyomo/contrib/solver/solvers/knitro/engine.py

@@ -11,7 +11,7 @@
 
 from collections.abc import Callable, Iterable, Mapping, MutableMapping, Sequence
 from types import MappingProxyType
-from typing import Any, Optional, TypeVar
+from typing import Any, TypeVar
 
 from pyomo.common.enums import ObjectiveSense
 from pyomo.common.errors import DeveloperError
@@ -92,7 +92,7 @@ def api_set_param(param_type: int) -> Callable[..., None]:
 
 def api_get_values(
     item_type: type[ItemType], value_type: ValueType
-) -> Callable[..., Optional[list[float]]]:
+) -> Callable[..., list[float] | None]:
     if item_type is VarData:
         if value_type == ValueType.PRIMAL:
             return knitro.KN_get_var_primal_values
@@ -108,7 +108,7 @@ def api_get_values(
     )
 
 
-def api_add_items(item_type: type[ItemType]) -> Callable[..., Optional[list[int]]]:
+def api_add_items(item_type: type[ItemType]) -> Callable[..., list[int] | None]:
     if item_type is VarData:
         return knitro.KN_add_vars
     elif item_type is ConstraintData:
@@ -169,11 +169,11 @@ class Engine:
 
     has_objective: bool
     maps: Mapping[type[ItemData], MutableMapping[int, int]]
-    nonlinear_map: MutableMapping[Optional[int], NonlinearExpressionData]
+    nonlinear_map: MutableMapping[int | None, NonlinearExpressionData]
     nonlinear_diff_order: int
 
-    _kc: Optional[Any]
-    _status: Optional[int]
+    _kc: Any | None
+    _status: int | None
 
     def __init__(self, *, nonlinear_diff_order: int = 2) -> None:
         self.has_objective = False
@@ -242,7 +242,7 @@ def set_options(self, **options) -> None:
         for param, val in options.items():
             self.set_option(param, val)
 
-    def set_outlev(self, level: Optional[int] = None) -> None:
+    def set_outlev(self, level: int | None = None) -> None:
         if level is None:
             level = knitro.KN_OUTLEV_ALL
         self.set_options(outlev=level)
@@ -289,7 +289,7 @@ def get_num_solutions(self) -> int:
     def get_solve_time(self) -> float:
         return self.execute(knitro.KN_get_solve_time_real)
 
-    def get_obj_value(self) -> Optional[float]:
+    def get_obj_value(self) -> float | None:
         if not self.has_objective:
             return None
         if self._status not in {
@@ -303,7 +303,7 @@ def get_obj_value(self) -> Optional[float]:
             return None
         return self.execute(knitro.KN_get_obj_value)
 
-    def get_obj_bound(self) -> Optional[float]:
+    def get_obj_bound(self) -> float | None:
         if not self.has_objective:
             return None
         return self.execute(knitro.KN_get_mip_relaxation_bnd)
@@ -319,7 +319,7 @@ def get_values(
         item_type: type[ItemType],
         value_type: ValueType,
         items: Iterable[ItemType],
-    ) -> Optional[list[float]]:
+    ) -> list[float] | None:
         func = api_get_values(item_type, value_type)
         idxs = self.get_idxs(item_type, items)
         return self.execute(func, idxs)
@@ -367,7 +367,7 @@ def set_con_structures(self, cons: Iterable[ConstraintData]) -> None:
     def set_obj_structures(self, obj: ObjectiveData) -> None:
         self.add_structures(None, obj.expr)
 
-    def add_structures(self, i: Optional[int], expr) -> None:
+    def add_structures(self, i: int | None, expr) -> None:
         repn = generate_standard_repn(expr)
         if repn is None:
             return
@@ -408,7 +408,7 @@ def add_structures(self, i: Optional[int], expr) -> None:
             )
 
     def add_callback(
-        self, i: Optional[int], expr: NonlinearExpressionData, callback: Callback
+        self, i: int | None, expr: NonlinearExpressionData, callback: Callback
     ) -> None:
         is_obj = i is None
         idx_cons = [i] if not is_obj else None
@@ -440,8 +440,6 @@ def register_callbacks(self) -> None:
         for i, expr in self.nonlinear_map.items():
             self.register_callback(i, expr)
 
-    def register_callback(
-        self, i: Optional[int], expr: NonlinearExpressionData
-    ) -> None:
+    def register_callback(self, i: int | None, expr: NonlinearExpressionData) -> None:
         callback = build_callback_handler(expr, idx=i).expand()
         self.add_callback(i, expr, callback)

pyomo/contrib/solver/solvers/knitro/package.py

@@ -10,7 +10,6 @@
 #  ___________________________________________________________________________
 
 import io
-from typing import Optional
 
 from pyomo.common.tee import TeeStream, capture_output
 from pyomo.contrib.solver.common.base import Availability
@@ -61,7 +60,7 @@ def create_context():
         return knitro.KN_new_lm(lmc)
 
     @staticmethod
-    def get_version() -> Optional[tuple[int, int, int]]:
+    def get_version() -> tuple[int, int, int] | None:
         """Get the version of the KNITRO solver as a tuple.
 
         Returns:
@@ -97,7 +96,7 @@ def check_availability() -> Availability:
 
 
 class PackageChecker:
-    _available_cache: Optional[Availability]
+    _available_cache: Availability | None
 
     def __init__(self) -> None:
         self._available_cache = None
@@ -107,5 +106,5 @@ def available(self) -> Availability:
             self._available_cache = Package.check_availability()
         return self._available_cache
 
-    def version(self) -> Optional[tuple[int, int, int]]:
+    def version(self) -> tuple[int, int, int] | None:
         return Package.get_version()

pyomo/contrib/solver/solvers/knitro/solution.py

@@ -10,7 +10,7 @@
 #  ___________________________________________________________________________
 
 from collections.abc import Mapping, Sequence
-from typing import Optional, Protocol
+from typing import Protocol
 
 from pyomo.contrib.solver.common.solution_loader import SolutionLoaderBase
 from pyomo.contrib.solver.solvers.knitro.typing import ItemType, ValueType
@@ -25,10 +25,10 @@ def get_values(
         self,
         item_type: type[ItemType],
         value_type: ValueType,
-        items: Optional[Sequence[ItemType]] = None,
+        items: Sequence[ItemType] | None = None,
         *,
         exists: bool,
-        solution_id: Optional[int] = None,
+        solution_id: int | None = None,
     ) -> Mapping[ItemType, float]: ...
 
 
@@ -60,7 +60,9 @@ def get_primals(self, vars_to_load=None):
         return self.get_vars(vars_to_load)
 
     def get_vars(
-        self, vars_to_load: Optional[Sequence[VarData]] = None, solution_id=None
+        self,
+        vars_to_load: Sequence[VarData] | None = None,
+        solution_id: int | None = None,
     ) -> Mapping[VarData, float]:
         return self._provider.get_values(
             VarData,
@@ -71,7 +73,9 @@ def get_vars(
         )
 
     def get_reduced_costs(
-        self, vars_to_load: Optional[Sequence[VarData]] = None, solution_id=None
+        self,
+        vars_to_load: Sequence[VarData] | None = None,
+        solution_id: int | None = None,
     ) -> Mapping[VarData, float]:
         return self._provider.get_values(
             VarData,
@@ -82,7 +86,9 @@ def get_reduced_costs(
         )
 
     def get_duals(
-        self, cons_to_load: Optional[Sequence[ConstraintData]] = None, solution_id=None
+        self,
+        cons_to_load: Sequence[ConstraintData] | None = None,
+        solution_id: int | None = None,
     ) -> Mapping[ConstraintData, float]:
         return self._provider.get_values(
             ConstraintData,

pyomo/contrib/solver/solvers/knitro/typing.py

@@ -10,7 +10,7 @@
 #  ___________________________________________________________________________
 
 from collections.abc import Callable
-from typing import Any, NamedTuple, Protocol, TypeVar, Union
+from typing import Any, NamedTuple, Protocol, TypeVar
 
 from pyomo.common.enums import Enum
 from pyomo.core.base.constraint import ConstraintData
@@ -38,7 +38,7 @@ def sign(self) -> float:
         return -1.0 if self == ValueType.DUAL else 1.0
 
 
-ItemData = Union[VarData, ConstraintData]
+ItemData = VarData | ConstraintData
 ItemType = TypeVar("ItemType", bound=ItemData)
 
 

pyomo/contrib/solver/solvers/knitro/utils.py

@@ -10,7 +10,6 @@
 #  ___________________________________________________________________________
 
 from collections.abc import Iterable, Mapping, MutableSet, Sequence
-from typing import Optional
 
 from pyomo.common.collections import ComponentMap, ComponentSet
 from pyomo.common.numeric_types import value
@@ -75,11 +74,11 @@ class KnitroModelData:
     variables: list[VarData]
     _vars: MutableSet[VarData]
 
-    def __init__(self, block: Optional[BlockData] = None) -> None:
+    def __init__(self, block: BlockData | None = None) -> None:
         """Initialize a Problem instance.
 
         Args:
-            block (Optional[BlockData]): Pyomo block to initialize from. If None,
+            block (BlockData | None): Pyomo block to initialize from. If None,
                 creates an empty problem that can be populated later.
 
         """