Merged in bugfix/fill_claim_type (pull request #874)

Bugfix/fill claim type

* Handle if AARETE_DERIVED_CLAIM_TYPE_CD comes in as list

* add unit tests

* Black format


Approved-by: Siddhant Medar

src/pipelines/shared/postprocessing/postprocessing_funcs.py

@@ -880,8 +880,15 @@ def fill_claim_type_from_title(df: pd.DataFrame) -> pd.DataFrame:
             file_mask = df["FILE_NAME"] == file_name
             file_rows = df.loc[file_mask, "AARETE_DERIVED_CLAIM_TYPE_CD"]
 
-            # Get non-empty values for this file
-            non_empty_values = [v for v in file_rows if not string_utils.is_empty(v)]
+            # Get non-empty values for this file, normalizing lists to strings
+            non_empty_values = []
+            for v in file_rows:
+                if not string_utils.is_empty(v):
+                    # Convert lists to their first element if present
+                    if isinstance(v, list) and len(v) > 0:
+                        non_empty_values.append(v[0])
+                    elif not isinstance(v, list):
+                        non_empty_values.append(v)
 
             if non_empty_values:
                 # Use mode (most common value) to fill empty rows in this file