Move to subfolder

- Makes python recognize it as a submodule

stat/utils/extractor.py

@@ -0,0 +1,23 @@
+import json
+from pathlib import Path
+import pandas as pd
+
+def extract_id(row: pd.Series) -> str:
+    """Extracts PGN from metadata or falls back to CAN ID."""
+    meta = row.get('j1939_metadata')
+    if pd.isna(meta):
+        return f"ID: {row['ID']}"
+    if isinstance(meta, str):
+        try:
+            meta = json.loads(meta)
+        except json.JSONDecodeError:
+            return f"ID: {row['ID']}"
+    if isinstance(meta, dict) and 'PGN' in meta:
+        return f"PGN: {meta['PGN']}"
+    return f"ID: {row['ID']}"
+
+def load_data(file_path: Path) -> pd.DataFrame:
+    """Loads Parquet file and adds an Identifier column."""
+    df = pd.read_parquet(file_path)
+    df['Identifier'] = df.apply(extract_id, axis=1)
+    return df