Implements Feature to cleanup authors freetext field

transform/base.py

@@ -0,0 +1,37 @@
+"""Base transform node for data pipeline."""
+from abc import ABC, abstractmethod
+import sqlite3
+import pandas as pd
+
+
+class TransformContext:
+    """Context object containing the dataframe for transformation."""
+    
+    def __init__(self, df: pd.DataFrame):
+        self.df = df
+    
+    def get_dataframe(self) -> pd.DataFrame:
+        """Get the pandas dataframe from the context."""
+        return self.df
+
+
+class TransformNode(ABC):
+    """Abstract base class for transformation nodes.
+    
+    Each transform node implements a single transformation step
+    that takes data from the database, transforms it, and 
+    potentially writes results back.
+    """
+    
+    @abstractmethod
+    def run(self, con: sqlite3.Connection, context: TransformContext) -> TransformContext:
+        """Execute the transformation.
+        
+        Args:
+            con: SQLite database connection
+            context: TransformContext containing the input dataframe
+            
+        Returns:
+            TransformContext with the transformed dataframe
+        """
+        pass