refactor: Make examples/topic_create.py modular and add docstrings (#513)

Signed-off-by: Muhammad Saad Sabir <[email protected]>
Signed-off-by: Muhammad Saad Sabir <[email protected]>

Author: msaadsbr

CHANGELOG.md

@@ -10,6 +10,7 @@ This changelog is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.
 - Unified balance and transfer logging format — both now consistently display values in hbars for clarity.
 
 ### Added
+- Refactored `examples/topic_create.py` into modular functions for better readability and reuse.
 - Add `examples/account_id.py` demonstrating AccountId class usage including creating standard AccountIds, parsing from strings, comparing instances, and creating AccountIds with public key aliases
 
 - Added Google-style docstrings to `CustomFractionalFee` class and its methods in `custom_fractional_fee.py`.

examples/topic_create.py

@@ -4,6 +4,7 @@
 """
 import os
 import sys
+from typing import Tuple
 from dotenv import load_dotenv
 
 from hiero_sdk_python import (
@@ -14,21 +15,44 @@
     Network,
 )
 
+# Load environment variables from .env file
 load_dotenv()
 
-# set up the Hedera client with operator credentials
-def setup_client():
+
+def setup_client() -> Tuple[Client, PrivateKey]:
+    """
+    Sets up and configures the Hiero client for the testnet.
+    Reads OPERATOR_ID and OPERATOR_KEY from environment variables.
+    """
     network = Network(network='testnet')
     client = Client(network)
 
-    operator_id = AccountId.from_string(os.getenv('OPERATOR_ID'))
-    operator_key = PrivateKey.from_string(os.getenv('OPERATOR_KEY'))
+    operator_id_str = os.getenv('OPERATOR_ID')
+    operator_key_str = os.getenv('OPERATOR_KEY')
+
+    # Check if the environment variables are loaded correctly
+    if not operator_id_str or not operator_key_str:
+        print("Error: OPERATOR_ID or OPERATOR_KEY not found in environment.")
+        print("Please create a .env file in the project's root directory with:")
+        print("\nOPERATOR_ID=your_id_here")
+        print("OPERATOR_KEY=your_key_here\n")
+        sys.exit(1)
+
+    try:
+        operator_id = AccountId.from_string(operator_id_str)
+        operator_key = PrivateKey.from_string(operator_key_str)
+    except (TypeError, ValueError) as e:
+        print(f"Error: Invalid OPERATOR_ID or OPERATOR_KEY format: {e}")
+        sys.exit(1)
 
     client.set_operator(operator_id, operator_key)
     return client, operator_key
 
-# create a new topic on Hedera network
-def create_topic(client, operator_key):
+
+def create_topic(client: Client, operator_key: PrivateKey):
+    """
+    Builds, signs, and executes a new topic creation transaction.
+    """
     transaction = (
         TopicCreateTransaction(
             memo="Python SDK created topic",
@@ -41,7 +65,7 @@ def create_topic(client, operator_key):
     try:
         receipt = transaction.execute(client)
         if receipt and receipt.topic_id:
-            print(f"Topic created with ID: {receipt.topic_id}")
+            print(f"Success! Topic created with ID: {receipt.topic_id}")
         else:
             print("Topic creation failed: Topic ID not returned in receipt.")
             sys.exit(1)
@@ -51,6 +75,9 @@ def create_topic(client, operator_key):
 
 
 def main():
+    """
+    Main workflow to set up the client and create a new topic.
+    """
     client, operator_key = setup_client()
     create_topic(client, operator_key)