fix: better valueerror message

src/psycop_feature_generation/timeseriesflattener/feature_spec_objects.py

@@ -262,15 +262,16 @@ class MinGroupSpec(BaseModel):
 
     allowed_nan_value_prop: list[float] = [0.0]
     # If NaN is higher than this in the input dataframe during resolution, raise an error.
-
+    
     def __init__(self, **data):
         super().__init__(**data)
 
         # Check that all passed loaders are valid
         invalid_loaders = list(set(self.values_loader) - set(data_loaders.get_all()))
         if len(invalid_loaders) != 0:
-            raise ValueError(f"""Following loaders were not found in data_loaders registry:{' '.join(str(loader) for loader in invalid_loaders)} 
-            Available loaders: {' '.join(str(loader) for loader in data_loaders.get_all())}""")
+            raise ValueError(f"""Invalid loader(s) specified. Following loaders were not found in the data_loaders registry:
+            {' '.join(str(loader) for loader in invalid_loaders)} 
+            Available loaders:{' '.join(str(loader) for loader in data_loaders.get_all())}""")
 
         if self.output_col_name_override:
             input_col_name = (
@@ -316,6 +317,7 @@ def create_specs_from_group(
 
     # Create all combinations of top level elements
     # For each attribute in the FeatureGroupSpec
+
     feature_group_spec_dict = feature_group_spec.__dict__
 
     permuted_dicts = create_feature_combinations_from_dict(d=feature_group_spec_dict)