solvers: allow silencing version output of highs (#479)

Author: maurerle

linopy/solvers.py

@@ -460,6 +460,7 @@ def solve_problem_from_file(
 
         # Use HiGHS to parse the problem file and find the set of variable names, needed to parse solution
         h = highspy.Highs()
+        h.silent()
         h.readModel(path_to_string(problem_fn))
         variables = {v.name for v in h.getVariables()}
 
@@ -755,11 +756,11 @@ def solve_problem_from_model(
             )
 
         h = model.to_highspy(explicit_coordinate_names=explicit_coordinate_names)
+        self._set_solver_params(h, log_fn)
 
         return self._solve(
             h,
             solution_fn,
-            log_fn,
             warmstart_fn,
             basis_fn,
             model=model,
@@ -804,23 +805,35 @@ def solve_problem_from_file(
 
         problem_fn_ = path_to_string(problem_fn)
         h = highspy.Highs()
+        self._set_solver_params(h, log_fn)
+
         h.readModel(problem_fn_)
 
         return self._solve(
             h,
             solution_fn,
-            log_fn,
             warmstart_fn,
             basis_fn,
             io_api=read_io_api_from_problem_file(problem_fn),
             sense=read_sense_from_problem_file(problem_fn),
         )
 
+    def _set_solver_params(
+        self,
+        highs_solver: highspy.Highs,
+        log_fn: Path | None = None,
+    ) -> None:
+        if log_fn is not None:
+            self.solver_options["log_file"] = path_to_string(log_fn)
+            logger.info(f"Log file at {self.solver_options['log_file']}")
+
+        for k, v in self.solver_options.items():
+            highs_solver.setOptionValue(k, v)
+
     def _solve(
         self,
         h: highspy.Highs,
         solution_fn: Path | None = None,
-        log_fn: Path | None = None,
         warmstart_fn: Path | None = None,
         basis_fn: Path | None = None,
         model: Model | None = None,
@@ -877,13 +890,6 @@ def _solve(
             highspy.HighsModelStatus.kUnknown: TerminationCondition.unknown,
         }
 
-        if log_fn is not None:
-            self.solver_options["log_file"] = path_to_string(log_fn)
-            logger.info(f"Log file at {self.solver_options['log_file']}")
-
-        for k, v in self.solver_options.items():
-            h.setOptionValue(k, v)
-
         if warmstart_fn is not None and warmstart_fn.suffix == ".sol":
             h.readSolution(path_to_string(warmstart_fn), 0)
         elif warmstart_fn: