refactor: clean up imports and improve gender normalization method

processing/steps/__init__.py

@@ -9,7 +9,7 @@ import pandas as pd
 from pydantic import BaseModel
 
 from core.config.pipeline_config import PipelineConfig
-from core.utils.data_loader import OPTIMIZED_DTYPES, DataLoader
+from core.utils.data_loader import DataLoader
 from processing.batch.batch_config import BatchConfig
 
 

processing/steps/feature_extraction_step.py

@@ -150,7 +150,8 @@ class FeatureExtractionStep(PipelineStep):
             except Exception as e:
                 logging.warning(f"NER tagging failed for row {idx}: {e}")
 
-    def _normalize_gender(self, series: pd.Series) -> pd.Series:
+    @classmethod
+    def _normalize_gender(cls, series: pd.Series) -> pd.Series:
         gender_mapping = {
             "m": "m",
             "male": "m",