adding docstring to classes

app/utils/data_processing.py

@@ -19,13 +19,17 @@ logger = logging.getLogger(__name__)
 class GTINProcessor:
     """Handles GTIN normalization and validation."""
 
-    VALID_LENGTHS = [8, 12, 13, 14]
+    VALID_LENGTHS = [8, 12, 13, 14]  # List of valid GTIN lengths
 
     def normalize(self, gtin_value: any) -> Optional[str]:
         """
         Normalize GTIN to proper format.
 
-        Returns None for invalid GTINs.
+        Args:
+            gtin_value (any): The GTIN value to be normalized.
+
+        Returns:
+            Optional[str]: The normalized GTIN string or None if the input is invalid.
         """
         if not gtin_value or pd.isna(gtin_value):
             return None
@@ -72,7 +76,15 @@ class GTINProcessor:
         return None
 
     def validate(self, gtin: str) -> bool:
-        """Validate GTIN format."""
+        """
+        Validate the GTIN format.
+
+        Args:
+            gtin (str): The GTIN string to be validated.
+
+        Returns:
+            bool: True if the GTIN is valid, False otherwise.
+        """
         if not gtin:
             return False
         return len(gtin) in self.VALID_LENGTHS and gtin.isdigit()
@@ -97,14 +109,15 @@ class PriceProcessor:
         r"([A-Z]{3})\s*([0-9.,]+)": lambda m: (m.group(2), m.group(1)),
     }
 
-    def parse_price_currency(
+    def parse_price_currency(self, price_str: any) -> Tuple[Optional[str], Optional[str]]:
-        self, price_str: any
-    ) -> Tuple[Optional[str], Optional[str]]:
         """
-        Parse price string into (price, currency) tuple.
+        Parse a price string to extract the numeric value and currency.
 
-        Raises ValueError if parsing fails for non-empty input.
+        Args:
-        Returns (None, None) for empty/null input.
+            price_str (any): The price string to be parsed.
+
+        Returns:
+            Tuple[Optional[str], Optional[str]]: A tuple containing the parsed price and currency, or None if parsing fails.
         """
         if not price_str or pd.isna(price_str):
             return None, None