refactor: use Client.from_env() in topic_create_transaction.py

CHANGELOG.md

@@ -128,6 +128,7 @@ This changelog is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.
 - Added dry-run support and refactored `.github/workflows/bot-workflows.yml` to use dedicated script `.github/scripts/bot-workflows.js` for improved maintainability and testability. (`#1288`)
 
 ### Changed
+- Refactored `examples/consensus/topic_create_transaction.py` to use `Client.from_env()` (#1611)
 - chore: format tests/unit/mock_server.py with black (#1542)
 - Updated actions/checkout to v6.0.1 and actions/github-script v8.0.0 in bot-next-issue-recommendation workflow (#1586)
 - Expanded inactivity bot messages to include `/unassign` command information for contributors (#1555)

examples/consensus/topic_create_transaction.py

@@ -2,58 +2,19 @@
 uv run examples/consensus/topic_create_transaction.py
 python examples/consensus/topic_create_transaction.py
 """
+from hiero_sdk_python import Client, TopicCreateTransaction
 
-import os
-import sys
-from typing import Tuple
-from dotenv import load_dotenv
-
-from hiero_sdk_python import (
-    Client,
-    AccountId,
-    PrivateKey,
-    TopicCreateTransaction,
-    Network,
-)
-
-# Load environment variables from .env file
-load_dotenv()
-network_name = os.getenv("NETWORK", "testnet").lower()
-
-
-def setup_client() -> Tuple[Client, PrivateKey]:
+def setup_client():
     """
-    Sets up and configures the Hiero client for the testnet.
-    Reads OPERATOR_ID and OPERATOR_KEY from environment variables.
+    Sets up and configures the Hiero client.
+    Reads OPERATOR_ID and OPERATOR_KEY from environment variables via Client.from_env().
     """
-    network = Network(network_name)
-    print(f"Connecting to Hedera {network_name} network!")
-    client = Client(network)
-
-    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)
+    client = Client.from_env()
+    print(f"Network: {client.network.network}")
     print(f"Client set up with operator id {client.operator_account_id}")
-    return client, operator_key
-
+    return client, client.operator_private_key
 
-def create_topic(client: Client, operator_key: PrivateKey):
+def create_topic(client: Client, operator_key: "PrivateKey"):
     """
     Builds, signs, and executes a new topic creation transaction.
     """
@@ -64,18 +25,16 @@ def create_topic(client: Client, operator_key: PrivateKey):
         .freeze_with(client)
         .sign(operator_key)
     )
-
     try:
         receipt = transaction.execute(client)
         if receipt and 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)
+            raise SystemExit(1)
     except Exception as e:
         print(f"Topic creation failed: {str(e)}")
-        sys.exit(1)
-
+        raise SystemExit(1)
 
 def main():
     """
@@ -84,6 +43,5 @@ def main():
     client, operator_key = setup_client()
     create_topic(client, operator_key)
 
-
 if __name__ == "__main__":
-    main()
+    main()