refactor(examples): modularize token_transfer.py for clarity and reuse (#773)

CHANGELOG.md

@@ -14,7 +14,6 @@ This changelog is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.
 - Refactored token-related example scripts (`token_delete.py`, `token_dissociate.py`, etc.) for improved readability and modularity. [#370]
 - upgrade: step security action upgraded from harden-runner-2.13.1 to harden-runner-2.13.1
 
-
 ### Fixed
 - chore: fixed integration test names without a test prefix or postfix
 

examples/token_transfer.py

@@ -0,0 +1,98 @@
+"""
+Example: Token Transfer Transaction (Modularized)
+
+This example demonstrates transferring tokens (HBARs or custom tokens)
+between two Hedera accounts using the Hiero Python SDK.
+It has been refactored for modularity and clarity.
+
+Functions:
+- setup_client(): Initializes and configures the Hedera client.
+- transfer_transaction(): Executes a token/HBAR transfer.
+- account_balance_query(): Checks the account balance post-transfer.
+- main(): Orchestrates the above functions.
+"""
+
+from hiero_sdk_python import (
+    Client,
+    AccountId,
+    PrivateKey,
+    TransferTransaction,
+    AccountBalanceQuery,
+    Hbar,
+)
+import os
+
+
+def setup_client() -> Client:
+    """
+    Set up the Hedera client for Testnet.
+
+    Returns:
+        Client: Configured Hedera client.
+    """
+    operator_id = AccountId.fromString(os.getenv("OPERATOR_ID", "0.0.1234"))
+    operator_key = PrivateKey.fromString(os.getenv("OPERATOR_KEY", "302e..."))
+    client = Client.for_testnet()
+    client.set_operator(operator_id, operator_key)
+    return client
+
+
+def transfer_transaction(
+    client: Client, sender: AccountId, receiver: AccountId, amount_tinybars: int
+) -> str:
+    """
+    Perform an HBAR transfer transaction between two accounts.
+
+    Args:
+        client (Client): The active Hedera client.
+        sender (AccountId): The sender account ID.
+        receiver (AccountId): The receiver account ID.
+        amount_tinybars (int): Amount to transfer in tinybars.
+
+    Returns:
+        str: The transaction ID.
+    """
+    print(f"🚀 Initiating transfer of {amount_tinybars} tinybars from {sender} to {receiver}...")
+    txn = (
+        TransferTransaction()
+        .add_hbar_transfer(sender, Hbar.fromTinybars(-amount_tinybars))
+        .add_hbar_transfer(receiver, Hbar.fromTinybars(amount_tinybars))
+        .execute(client)
+    )
+    receipt = txn.get_receipt(client)
+    print(f"✅ Transfer complete. Status: {receipt.status}")
+    return str(txn.transaction_id)
+
+
+def account_balance_query(client: Client, account_id: AccountId) -> None:
+    """
+    Query and print the account balance.
+
+    Args:
+        client (Client): The active Hedera client.
+        account_id (AccountId): The account to query.
+    """
+    balance = AccountBalanceQuery().set_account_id(account_id).execute(client)
+    print(f"💰 Balance for {account_id}: {balance.hbars.toTinybars()} tinybars")
+
+
+def main() -> None:
+    """
+    Main entry point to perform token transfer and balance verification.
+    """
+    client = setup_client()
+
+    sender = AccountId.fromString(os.getenv("SENDER_ID", "0.0.1234"))
+    receiver = AccountId.fromString(os.getenv("RECEIVER_ID", "0.0.5678"))
+    amount_tinybars = int(os.getenv("TRANSFER_AMOUNT", "1000"))
+
+    txn_id = transfer_transaction(client, sender, receiver, amount_tinybars)
+
+    print(f"🔍 Transaction ID: {txn_id}")
+    print("\n📊 Checking updated balances:")
+    account_balance_query(client, sender)
+    account_balance_query(client, receiver)
+
+
+if __name__ == "__main__":
+    main()