Use the variable name _ for unused return values

test/functional/mempool_packages.py

@@ -213,7 +213,7 @@ class MempoolPackagesTest(BitcoinTestFramework):
         value = send_value
 
         # Create tx1
-        (tx1_id, tx1_value) = self.chain_transaction(self.nodes[0], tx0_id, 0, value, fee, 1)
+        tx1_id, _ = self.chain_transaction(self.nodes[0], tx0_id, 0, value, fee, 1)
 
         # Create tx2-7
         vout = 1