Refine type hints: use np alias and add overloads

Improve typing in src/pyscipopt/scip.pyi: import Union and overload, alias numpy as np, and switch class bases from numpy.ndarray to np.ndarray. Add overloads for Model.getSolVal and Model.getVal to distinguish scalar returns (Expr/GenExpr -> float) from matrix returns (MatrixExpr -> np.ndarray), improving type accuracy for consumers and IDE/type-checkers.

Author: Zeroto521

src/pyscipopt/scip.pyi

@@ -1,6 +1,6 @@
-from typing import ClassVar
+from typing import ClassVar, Union, overload
 
-import numpy
+import numpy as np
 from _typeshed import Incomplete
 from typing_extensions import disjoint_base
 
@@ -496,7 +496,7 @@ class LP:
     def solve(self, dual: Incomplete = ...) -> Incomplete: ...
     def writeLP(self, filename: Incomplete) -> Incomplete: ...
 
-class MatrixConstraint(numpy.ndarray):
+class MatrixConstraint(np.ndarray):
     def getConshdlrName(self) -> Incomplete: ...
     def isActive(self) -> Incomplete: ...
     def isChecked(self) -> Incomplete: ...
@@ -512,7 +512,7 @@ class MatrixConstraint(numpy.ndarray):
     def isSeparated(self) -> Incomplete: ...
     def isStickingAtNode(self) -> Incomplete: ...
 
-class MatrixExpr(numpy.ndarray):
+class MatrixExpr(np.ndarray):
     def _evaluate(self, sol: Incomplete) -> Incomplete: ...
     def __array_ufunc__(
         self,
@@ -522,7 +522,7 @@ class MatrixExpr(numpy.ndarray):
         **kwargs: Incomplete,
     ) -> Incomplete: ...
 
-class MatrixExprCons(numpy.ndarray):
+class MatrixExprCons(np.ndarray):
     def __array_ufunc__(
         self,
         ufunc: Incomplete,
@@ -1215,7 +1215,10 @@ class Model:
         self, sol: Incomplete, original: Incomplete = ...
     ) -> Incomplete: ...
     def getSolTime(self, sol: Incomplete) -> Incomplete: ...
-    def getSolVal(self, sol: Incomplete, expr: Incomplete) -> Incomplete: ...
+    @overload
+    def getSolVal(self, sol: Solution, expr: Union[Expr, GenExpr]) -> float: ...
+    @overload
+    def getSolVal(self, sol: Solution, expr: MatrixExpr) -> np.ndarray: ...
     def getSols(self) -> Incomplete: ...
     def getSolvingTime(self) -> Incomplete: ...
     def getStage(self) -> Incomplete: ...
@@ -1227,7 +1230,10 @@ class Model:
     def getTransformedCons(self, cons: Incomplete) -> Incomplete: ...
     def getTransformedVar(self, var: Incomplete) -> Incomplete: ...
     def getTreesizeEstimation(self) -> Incomplete: ...
-    def getVal(self, expr: Incomplete) -> Incomplete: ...
+    @overload
+    def getVal(self, expr: Union[Expr, GenExpr]) -> float: ...
+    @overload
+    def getVal(self, expr: MatrixExpr) -> np.ndarray: ...
     def getValsLinear(self, cons: Incomplete) -> Incomplete: ...
     def getVarDict(self, transformed: Incomplete = ...) -> Incomplete: ...
     def getVarLbDive(self, var: Incomplete) -> Incomplete: ...