[#167] Refactor _get_model_parameters()

hlink/linking/model_exploration/link_step_train_test_models.py

@@ -687,9 +687,6 @@ def _custom_param_grid_builder(
 
 
 def _get_model_parameters(training_config: dict[str, Any]) -> list[dict[str, Any]]:
-    model_parameters = training_config["model_parameters"]
-    model_parameter_search = training_config.get("model_parameter_search")
-
     if "param_grid" in training_config:
         print(
             dedent(
@@ -705,6 +702,11 @@ def _get_model_parameters(training_config: dict[str, Any]) -> list[dict[str, Any
             ),
             file=sys.stderr,
         )
+
+    model_parameters = training_config["model_parameters"]
+    model_parameter_search = training_config.get("model_parameter_search")
+    use_param_grid = training_config.get("param_grid", False)
+
     if model_parameter_search is not None:
         strategy = model_parameter_search["strategy"]
         if strategy == "explicit":
@@ -713,8 +715,8 @@ def _get_model_parameters(training_config: dict[str, Any]) -> list[dict[str, Any
             return _custom_param_grid_builder(model_parameters)
         else:
             raise ValueError(f"Unknown model_parameter_search strategy '{strategy}'")
-    elif "param_grid" in training_config and training_config["param_grid"]:
-        model_parameters = _custom_param_grid_builder(model_parameters)
+    elif use_param_grid:
+        return _custom_param_grid_builder(model_parameters)
     elif model_parameters == []:
         raise ValueError(
             "No model parameters found. In 'training' config, either supply 'model_parameters' or 'param_grid'."