docs: Add docstrings to custom_royalty_fee.py (#547)

Signed-off-by: Pranay <[email protected]>

Author: Pranay22077

CHANGELOG.md

@@ -18,6 +18,7 @@ This changelog is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.
 - Added documentation for resolving changelog conflicts in `docs/common_issues.md`
 - - Added comprehensive changelog entry guide at `docs/sdk_developers/changelog.md` to help contributors create proper changelog entries (#532).
 - docs: Added Google-style docstrings to `CustomFixedFee` class and its methods in `custom_fixed_fee.py`.
+- docs: Add Google-style docstrings to `CustomRoyaltyFee` class and its methods in `custom_royalty_fee.py`.
 
 ### Changed
 

src/hiero_sdk_python/tokens/custom_royalty_fee.py

@@ -7,10 +7,21 @@
     from hiero_sdk_python.tokens.custom_fixed_fee import CustomFixedFee
     from hiero_sdk_python.hapi.services import custom_fees_pb2
 
+"""Manages custom royalty fees for Non-Fungible Token (NFT) transactions.
+
+This module defines the CustomRoyaltyFee class, which allows a percentage-based 
+fee (with an optional fixed fee fallback) to be collected upon NFT transfer.
+"""
+
 
 class CustomRoyaltyFee(CustomFee):
-    """
-    Represents a custom royalty fee.
+    """Represents a custom royalty fee assessed during NFT transfers.
+
+    The royalty fee is defined by a fractional exchange value (numerator/denominator) 
+    and an optional fixed fee that applies if the NFT is exchanged for HBAR 
+    or a token not specified in the fee schedule.
+
+    Inherits common properties like fee_collector_account_id from CustomFee.
     """
 
     def __init__(
@@ -21,30 +32,77 @@ def __init__(
         fee_collector_account_id: typing.Optional["AccountId"] = None,
         all_collectors_are_exempt: bool = False,
     ):
+        """Initializes the CustomRoyaltyFee.
+
+        Args:
+            numerator (int): The numerator of the fraction defining the royalty amount. 
+                Defaults to 0.
+            denominator (int): The denominator of the fraction defining the royalty 
+                amount. Defaults to 1.
+            fallback_fee (typing.Optional[CustomFixedFee]): The fixed fee to be 
+                collected if the exchange is not in the token's unit (e.g., if sold 
+                for HBAR). Defaults to None.
+            fee_collector_account_id (typing.Optional[AccountId]): The account ID of 
+                the fee collector. Inherited from CustomFee. Defaults to None.
+            all_collectors_are_exempt (bool): If true, all collectors for this fee 
+                are exempt from custom fees. Inherited from CustomFee. Defaults to False.
+        """
         super().__init__(fee_collector_account_id, all_collectors_are_exempt)
         self.numerator = numerator
         self.denominator = denominator
         self.fallback_fee = fallback_fee
 
     def set_numerator(self, numerator: int) -> "CustomRoyaltyFee":
+        """Sets the numerator of the royalty fraction.
+
+        Args:
+            numerator (int): The numerator value (e.g., 5 for 5/100).
+
+        Returns:
+            CustomRoyaltyFee: This CustomRoyaltyFee instance for chaining.
+        """
         self.numerator = numerator
         return self
 
     def set_denominator(self, denominator: int) -> "CustomRoyaltyFee":
+        """Sets the denominator of the royalty fraction.
+
+        Args:
+            denominator (int): The denominator value (e.g., 100 for 5/100).
+
+        Returns:
+            CustomRoyaltyFee: This CustomRoyaltyFee instance for chaining.
+        """
         self.denominator = denominator
         return self
 
     def set_fallback_fee(self, fallback_fee: typing.Optional["CustomFixedFee"]) -> "CustomRoyaltyFee":
+        """Sets the optional fixed fee that applies if the royalty is paid in HBAR.
+
+        Args:
+            fallback_fee (typing.Optional[CustomFixedFee]): A CustomFixedFee object 
+                to use as the fixed fallback fee, or None to remove it.
+
+        Returns:
+            CustomRoyaltyFee: This CustomRoyaltyFee instance for chaining.
+        """
         self.fallback_fee = fallback_fee
         return self
 
     def _to_proto(self) -> "custom_fees_pb2.CustomFee":
+        """Converts this CustomRoyaltyFee object to its protobuf representation.
+
+        Builds the RoyaltyFee message and integrates it with the common fields
+        from the CustomFee parent class into a CustomFee protobuf message.
+
+        Returns:
+            custom_fees_pb2.CustomFee: The protobuf CustomFee message.
+        """
         from hiero_sdk_python.hapi.services import custom_fees_pb2
         from hiero_sdk_python.hapi.services.basic_types_pb2 import Fraction
 
         fallback_fee_proto = None
         if self.fallback_fee:
-            # Use _to_proto instead of _to_protobuf
             fallback_fee_proto = self.fallback_fee._to_proto().fixed_fee
 
         return custom_fees_pb2.CustomFee(
@@ -61,19 +119,29 @@ def _to_proto(self) -> "custom_fees_pb2.CustomFee":
 
     @classmethod
     def _from_proto(cls, proto_fee) -> "CustomRoyaltyFee":
-        """Create CustomRoyaltyFee from protobuf CustomFee message."""
+        """Creates a CustomRoyaltyFee instance from a CustomFee protobuf message.
+
+        Extracts the royalty fee details, optional fallback fee, and common fee 
+        properties from the protobuf message.
+
+        Args:
+            proto_fee: The protobuf CustomFee message. It is expected that the 
+                `royalty_fee` field is set.
+
+        Returns:
+            CustomRoyaltyFee: The corresponding CustomRoyaltyFee object.
+        """
         from hiero_sdk_python.account.account_id import AccountId
         from hiero_sdk_python.tokens.custom_fixed_fee import CustomFixedFee
 
         royalty_fee_proto = proto_fee.royalty_fee
 
         fallback_fee = None
         if royalty_fee_proto.HasField("fallback_fee"):
-            # Use the existing _from_fixed_fee_proto method
             fallback_fee = CustomFixedFee._from_fixed_fee_proto(royalty_fee_proto.fallback_fee)
 
         fee_collector_account_id = None
-        if proto_fee.HasField("fee_collector_account_id"):  # Changed from WhichOneof
+        if proto_fee.HasField("fee_collector_account_id"):
             fee_collector_account_id = AccountId._from_proto(proto_fee.fee_collector_account_id)
 
         return cls(