Add type variable for solver's environment type

Author: coroa

.gitignore

@@ -1,6 +1,7 @@
 .coverage
 .eggs
 .DS_Store
+.mypy_cache
 linopy/__pycache__
 test/__pycache__
 linopy.egg-info

linopy/solvers.py

@@ -17,7 +17,7 @@
 from collections import namedtuple
 from collections.abc import Callable, Generator
 from pathlib import Path
-from typing import TYPE_CHECKING, Any
+from typing import TYPE_CHECKING, Any, Generic, TypeVar
 
 import numpy as np
 import pandas as pd
@@ -36,6 +36,8 @@
 
     from linopy.model import Model
 
+EnvType = TypeVar("EnvType")
+
 QUADRATIC_SOLVERS = [
     "gurobi",
     "xpress",
@@ -197,7 +199,7 @@ def maybe_adjust_objective_sign(
     return solution
 
 
-class Solver(ABC):
+class Solver(ABC, Generic[EnvType]):
     """
     Abstract base class for solving a given linear problem.
 
@@ -244,7 +246,7 @@ def solve_problem_from_model(
         log_fn: Path | None = None,
         warmstart_fn: Path | None = None,
         basis_fn: Path | None = None,
-        env: None = None,
+        env: EnvType | None = None,
         explicit_coordinate_names: bool = False,
     ) -> Result:
         """
@@ -264,7 +266,7 @@ def solve_problem_from_file(
         log_fn: Path | None = None,
         warmstart_fn: Path | None = None,
         basis_fn: Path | None = None,
-        env: None = None,
+        env: EnvType | None = None,
     ) -> Result:
         """
         Abstract method to solve a linear problem from a problem file.
@@ -283,7 +285,7 @@ def solve_problem(
         log_fn: Path | None = None,
         warmstart_fn: Path | None = None,
         basis_fn: Path | None = None,
-        env: None = None,
+        env: EnvType | None = None,
         explicit_coordinate_names: bool = False,
     ) -> Result:
         """
@@ -324,7 +326,7 @@ def solver_name(self) -> SolverName:
         return SolverName[self.__class__.__name__]
 
 
-class CBC(Solver):
+class CBC(Solver[None]):
     """
     Solver subclass for the CBC solver.
 
@@ -505,7 +507,7 @@ def get_solver_solution() -> Solution:
         return Result(status, solution, CbcModel(mip_gap, runtime))
 
 
-class GLPK(Solver):
+class GLPK(Solver[None]):
     """
     Solver subclass for the GLPK solver.
 
@@ -675,7 +677,7 @@ def get_solver_solution() -> Solution:
         return Result(status, solution)
 
 
-class Highs(Solver):
+class Highs(Solver[None]):
     """
     Solver subclass for the Highs solver. Highs must be installed
     for usage. Find the documentation at https://www.maths.ed.ac.uk/hall/HiGHS/.
@@ -921,7 +923,7 @@ def get_solver_solution() -> Solution:
         return Result(status, solution, h)
 
 
-class Gurobi(Solver):
+class Gurobi(Solver[gurobipy.Env | dict[str, Any] | None]):
     """
     Solver subclass for the gurobi solver.
 
@@ -1156,7 +1158,7 @@ def get_solver_solution() -> Solution:
         return Result(status, solution, m)
 
 
-class Cplex(Solver):
+class Cplex(Solver[None]):
     """
     Solver subclass for the Cplex solver.
 
@@ -1312,7 +1314,7 @@ def get_solver_solution() -> Solution:
         return Result(status, solution, m)
 
 
-class SCIP(Solver):
+class SCIP(Solver[None]):
     """
     Solver subclass for the SCIP solver.
 
@@ -1465,7 +1467,7 @@ def get_solver_solution() -> Solution:
         return Result(status, solution, m)
 
 
-class Xpress(Solver):
+class Xpress(Solver[None]):
     """
     Solver subclass for the xpress solver.
 
@@ -1602,7 +1604,7 @@ def get_solver_solution() -> Solution:
 mosek_bas_re = re.compile(r" (XL|XU)\s+([^ \t]+)\s+([^ \t]+)| (LL|UL|BS)\s+([^ \t]+)")
 
 
-class Mosek(Solver):
+class Mosek(Solver[None]):
     """
     Solver subclass for the Mosek solver.
 
@@ -1932,7 +1934,7 @@ def get_solver_solution() -> Solution:
         return Result(status, solution)
 
 
-class COPT(Solver):
+class COPT(Solver[None]):
     """
     Solver subclass for the COPT solver.
 
@@ -2073,7 +2075,7 @@ def get_solver_solution() -> Solution:
         return Result(status, solution, m)
 
 
-class MindOpt(Solver):
+class MindOpt(Solver[None]):
     """
     Solver subclass for the MindOpt solver.
 
@@ -2216,7 +2218,7 @@ def get_solver_solution() -> Solution:
         return Result(status, solution, m)
 
 
-class PIPS(Solver):
+class PIPS(Solver[None]):
     """
     Solver subclass for the PIPS solver.
     """

test/test_solvers.py

@@ -7,9 +7,11 @@
 
 from pathlib import Path
 
+import pandas as pd
 import pytest
+import xarray as xr
 
-from linopy import solvers
+from linopy import LESS_EQUAL, Model, solvers
 
 free_mps_problem = """NAME               sample_mip
 ROWS
@@ -44,6 +46,22 @@
 """
 
 
+@pytest.fixture
+def model() -> Model:
+    m = Model()
+
+    x = m.add_variables(4, pd.Series([8, 10]), name="x")
+    y = m.add_variables(0, pd.DataFrame([[1, 2], [3, 4]]), name="y")
+
+    m.add_constraints(x + y, LESS_EQUAL, 10)
+
+    m.add_objective(2 * x + 3 * y)
+
+    m.parameters["param"] = xr.DataArray([1, 2, 3, 4], dims=["x"])
+
+    return m
+
+
 @pytest.mark.parametrize("solver", set(solvers.available_solvers))
 def test_free_mps_solution_parsing(solver: str, tmp_path: Path) -> None:
     try:
@@ -64,3 +82,29 @@ def test_free_mps_solution_parsing(solver: str, tmp_path: Path) -> None:
 
     assert result.status.is_ok
     assert result.solution.objective == 30.0
+
+
+@pytest.mark.skipif(
+    "gurobi" not in set(solvers.available_solvers), reason="Gurobi is not installed"
+)
+def test_gurobi_environment_parameters(model: Model, tmp_path: Path) -> None:
+    gurobi = solvers.Gurobi()
+
+    mps_file = tmp_path / "problem.mps"
+    mps_file.write_text(free_mps_problem)
+    sol_file = tmp_path / "solution.sol"
+
+    log1_file = tmp_path / "gurobi1.log"
+    result = gurobi.solve_problem(
+        problem_fn=mps_file, solution_fn=sol_file, env={"LogFile": str(log1_file)}
+    )
+
+    assert result.status.is_ok
+    assert log1_file.exists()
+
+    log2_file = tmp_path / "gurobi2.log"
+    gurobi.solve_problem(
+        model=model, solution_fn=sol_file, env={"LogFile": str(log2_file)}
+    )
+    assert result.status.is_ok
+    assert log2_file.exists()