refactor: use Client.from_env() in file_create_transaction example (hiero-ledger#1790)

Signed-off-by: anushka7426 <anushkaditharam@gmail.com>
Signed-off-by: exploreriii <133720349+exploreriii@users.noreply.github.com>
Co-authored-by: exploreriii <133720349+exploreriii@users.noreply.github.com>
Co-authored-by: Manish Dait <90558243+manishdait@users.noreply.github.com>

Author: 3 people

CHANGELOG.md

@@ -16,6 +16,7 @@ This changelog is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.
 - 
 
 ### Examples
+- Refactor `examples/file/file_create_transaction.py` to remove `os`,`dotenv`,`AccountId`,`PrivateKey`,`Network` imports that are no longer needed and updated setup-client() (#1610)
 
 - Refactored contract_delete_transaction example to use Client.from_env. (#1823)
 
@@ -302,6 +303,7 @@ This changelog is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.
 - chore: clarify wording in the bot-assignment-check.sh (#1748)
 - Refactored SDK dependencies to use version ranges, moved build-only deps out of runtime, removed unused core deps and added optional extras.
 
+   
 ### Fixed
 - Added a fork guard condition to prevent Codecov upload failures on fork PRs due to missing token. (`#1485`)
 - Corrected broken documentation links in SDK developer training files.(#1707)

examples/file/file_create_transaction.py

@@ -7,8 +7,9 @@
 python examples/file_create_transaction.py
 
 """
-import os
+
 import sys
+import os
 
 from dotenv import load_dotenv
 
@@ -21,20 +22,10 @@
 from hiero_sdk_python.file.file_create_transaction import FileCreateTransaction
 from hiero_sdk_python.response_code import ResponseCode
 
-load_dotenv()
-
-network_name = os.getenv("NETWORK", "testnet").lower()
-
-
 def setup_client():
     """Initialize and set up the client with operator account."""
-    network = Network(network_name)
-    print(f"Connecting to Hedera {network_name} network!")
-    client = Client(network)
-
-    operator_id = AccountId.from_string(os.getenv("OPERATOR_ID", ""))
-    operator_key = PrivateKey.from_string(os.getenv("OPERATOR_KEY", ""))
-    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