test: Avoid F541 (f-string without any placeholders)

contrib/tracing/log_raw_p2p_msgs.py

@@ -117,9 +117,9 @@ int trace_outbound_message(struct pt_regs *ctx) {
 
 
 def print_message(event, inbound):
-    print(f"%s %s msg '%s' from peer %d (%s, %s) with %d bytes: %s" %
-          (
-              f"Warning: incomplete message (only %d out of %d bytes)!" % (
+    print("{} {} msg '{}' from peer {} ({}, {}) with {} bytes: {}".format(
+
+              "Warning: incomplete message (only {} out of {} bytes)!".format(
                   len(event.msg), event.msg_size) if len(event.msg) < event.msg_size else "",
               "inbound" if inbound else "outbound",
               event.msg_type.decode("utf-8"),

test/functional/feature_anchors.py

@@ -102,7 +102,7 @@ class AnchorsTest(BitcoinTestFramework):
         self.nodes[0].addconnection(ONION_ADDR, 'block-relay-only', v2transport=False)
 
         self.log.debug("Stop node")
-        with self.nodes[0].assert_debug_log([f"DumpAnchors: Flush 1 outbound block-relay-only peer addresses to anchors.dat"]):
+        with self.nodes[0].assert_debug_log(["DumpAnchors: Flush 1 outbound block-relay-only peer addresses to anchors.dat"]):
             self.stop_node(0)
         # Manually close keep_alive proxy connection
         onion_proxy.stop()

test/functional/feature_assumeutxo.py

@@ -165,8 +165,8 @@ class AssumeutxoTest(BitcoinTestFramework):
             with self.nodes[0].assert_debug_log([log_msg]):
                 self.nodes[0].assert_start_raises_init_error(expected_msg=error_msg)
 
-        expected_error_msg = f"Error: A fatal internal error occurred, see debug.log for details: Assumeutxo data not found for the given blockhash '7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a'."
-        error_details = f"Assumeutxo data not found for the given blockhash"
+        expected_error_msg = "Error: A fatal internal error occurred, see debug.log for details: Assumeutxo data not found for the given blockhash '7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a7a'."
+        error_details = "Assumeutxo data not found for the given blockhash"
         expected_error(log_msg=error_details, error_msg=expected_error_msg)
 
         # resurrect node again
@@ -417,7 +417,7 @@ class AssumeutxoTest(BitcoinTestFramework):
 
         assert_equal(n0.getblockchaininfo()["blocks"], FINAL_HEIGHT)
 
-        self.log.info(f"Check that dumptxoutset works for past block heights")
+        self.log.info("Check that dumptxoutset works for past block heights")
         # rollback defaults to the snapshot base height
         dump_output2 = n0.dumptxoutset('utxos2.dat', "rollback")
         check_dump_output(dump_output2)

test/functional/feature_config_args.py

@@ -72,7 +72,7 @@ class ConfArgsTest(BitcoinTestFramework):
 
         self.log.debug('Verifying garbage in config can be detected')
         with open(conf_path, 'a', encoding='utf-8') as conf:
-            conf.write(f'garbage\n')
+            conf.write('garbage\n')
         self.nodes[0].assert_start_raises_init_error(
             extra_args=['-regtest'],
             expected_msg='Error: Error reading configuration file: parse error on line 1: garbage',
@@ -98,7 +98,7 @@ class ConfArgsTest(BitcoinTestFramework):
 
         # Check that startup fails if conf= is set in bitcoin.conf or in an included conf file
         bad_conf_file_path = self.nodes[0].datadir_path / "bitcoin_bad.conf"
-        util.write_config(bad_conf_file_path, n=0, chain='', extra_config=f'conf=some.conf\n')
+        util.write_config(bad_conf_file_path, n=0, chain='', extra_config='conf=some.conf\n')
         conf_in_config_file_err = 'Error: Error reading configuration file: conf cannot be set in the configuration file; use includeconf= if you want to include additional config files'
         self.nodes[0].assert_start_raises_init_error(
             extra_args=[f'-conf={bad_conf_file_path}'],

test/functional/feature_dersig.py

@@ -130,7 +130,7 @@ class BIP66Test(BitcoinTestFramework):
         block.hashMerkleRoot = block.calc_merkle_root()
         block.solve()
 
-        with self.nodes[0].assert_debug_log(expected_msgs=[f'Block validation error: mandatory-script-verify-flag-failed (Non-canonical DER signature)']):
+        with self.nodes[0].assert_debug_log(expected_msgs=['Block validation error: mandatory-script-verify-flag-failed (Non-canonical DER signature)']):
             peer.send_and_ping(msg_block(block))
             assert_equal(int(self.nodes[0].getbestblockhash(), 16), tip)
             peer.sync_with_ping()

test/functional/feature_framework_miniwallet.py

@@ -34,7 +34,7 @@ class FeatureFrameworkMiniWalletTest(BitcoinTestFramework):
 
     def test_wallet_tagging(self):
         """Verify that tagged wallet instances are able to send funds."""
-        self.log.info(f"Test tagged wallet instances...")
+        self.log.info("Test tagged wallet instances...")
         node = self.nodes[0]
         untagged_wallet = self.wallets[0][1]
         for i in range(10):

test/functional/feature_loadblock.py

@@ -51,8 +51,8 @@ class LoadblockTest(BitcoinTestFramework):
             cfg.write(f"port={node_url.port}\n")
             cfg.write(f"host={node_url.hostname}\n")
             cfg.write(f"output_file={bootstrap_file}\n")
-            cfg.write(f"max_height=100\n")
-            cfg.write(f"netmagic=fabfb5da\n")
+            cfg.write("max_height=100\n")
+            cfg.write("netmagic=fabfb5da\n")
             cfg.write(f"input={blocks_dir}\n")
             cfg.write(f"genesis={genesis_block}\n")
             cfg.write(f"hashlist={hash_list.name}\n")

test/functional/interface_rest.py

@@ -209,7 +209,7 @@ class RESTTest (BitcoinTestFramework):
         self.test_rest_request(f"/getutxos/{spending[0]}-+1", ret_type=RetType.OBJ, status=400)
         self.test_rest_request(f"/getutxos/{spending[0]}--1", ret_type=RetType.OBJ, status=400)
         self.test_rest_request(f"/getutxos/{spending[0]}aa-1234", ret_type=RetType.OBJ, status=400)
-        self.test_rest_request(f"/getutxos/aa-1234", ret_type=RetType.OBJ, status=400)
+        self.test_rest_request("/getutxos/aa-1234", ret_type=RetType.OBJ, status=400)
 
         # Test limits
         long_uri = '/'.join([f"{txid}-{n_}" for n_ in range(20)])

test/functional/interface_usdt_utxocache.py

@@ -393,7 +393,7 @@ class UTXOCacheTracepointTest(BitcoinTestFramework):
         bpf = BPF(text=utxocache_flushes_program, usdt_contexts=[ctx], debug=0, cflags=["-Wno-error=implicit-function-declaration"])
         bpf["utxocache_flush"].open_perf_buffer(handle_utxocache_flush)
 
-        self.log.info(f"prune blockchain to trigger a flush for pruning")
+        self.log.info("prune blockchain to trigger a flush for pruning")
         expected_flushes.append({"mode": "NONE", "for_prune": True, "size": 0})
         self.nodes[0].pruneblockchain(315)
 
@@ -401,7 +401,7 @@ class UTXOCacheTracepointTest(BitcoinTestFramework):
         bpf.cleanup()
 
         self.log.info(
-            f"check that we don't expect additional flushes and that the handle_* function succeeded")
+            "check that we don't expect additional flushes and that the handle_* function succeeded")
         assert_equal(0, len(expected_flushes))
         assert_equal(EXPECTED_HANDLE_FLUSH_SUCCESS, handle_flush_succeeds)
 

test/functional/mempool_datacarrier.py

@@ -26,7 +26,7 @@ class DataCarrierTest(BitcoinTestFramework):
             [],
             ["-datacarrier=0"],
             ["-datacarrier=1", f"-datacarriersize={MAX_OP_RETURN_RELAY - 1}"],
-            ["-datacarrier=1", f"-datacarriersize=2"],
+            ["-datacarrier=1", "-datacarriersize=2"],
         ]
 
     def test_null_data_transaction(self, node: TestNode, data, success: bool) -> None:

test/functional/mempool_truc.py

@@ -231,7 +231,7 @@ class MempoolTRUC(BitcoinTestFramework):
         assert_greater_than_or_equal(TRUC_CHILD_MAX_VSIZE, tx_v3_child_large2["tx"].get_vsize())
         assert_greater_than(tx_v3_parent_large2["tx"].get_vsize() + tx_v3_child_large2["tx"].get_vsize(), 10000)
 
-        assert_raises_rpc_error(-26, f"too-long-mempool-chain, exceeds ancestor size limit", node.sendrawtransaction, tx_v3_child_large2["hex"])
+        assert_raises_rpc_error(-26, "too-long-mempool-chain, exceeds ancestor size limit", node.sendrawtransaction, tx_v3_child_large2["hex"])
         self.check_mempool([tx_v3_parent_large2["txid"]])
 
     @cleanup(extra_args=["-datacarriersize=1000"])

test/functional/p2p_handshake.py

@@ -86,7 +86,7 @@ class P2PHandshakeTest(BitcoinTestFramework):
                                           DESIRABLE_SERVICE_FLAGS_PRUNED, expect_disconnect=False)
 
         self.log.info("Check that feeler connections get disconnected immediately")
-        with node.assert_debug_log([f"feeler connection completed"]):
+        with node.assert_debug_log(["feeler connection completed"]):
             self.add_outbound_connection(node, "feeler", NODE_NONE, wait_for_disconnect=True)
 
         self.log.info("Check that connecting to ourself leads to immediate disconnect")

test/functional/rpc_dumptxoutset.py

@@ -67,14 +67,14 @@ class DumptxoutsetTest(BitcoinTestFramework):
         assert_raises_rpc_error(
             -8, "Couldn't open file {}.incomplete for writing".format(invalid_path), node.dumptxoutset, invalid_path, "latest")
 
-        self.log.info(f"Test that dumptxoutset with unknown dump type fails")
+        self.log.info("Test that dumptxoutset with unknown dump type fails")
         assert_raises_rpc_error(
             -8, 'Invalid snapshot type "bogus" specified. Please specify "rollback" or "latest"', node.dumptxoutset, 'utxos.dat', "bogus")
 
-        self.log.info(f"Test that dumptxoutset failure does not leave the network activity suspended when it was on previously")
+        self.log.info("Test that dumptxoutset failure does not leave the network activity suspended when it was on previously")
         self.check_expected_network(node, True)
 
-        self.log.info(f"Test that dumptxoutset failure leaves the network activity suspended when it was off")
+        self.log.info("Test that dumptxoutset failure leaves the network activity suspended when it was off")
         node.setnetworkactive(False)
         self.check_expected_network(node, False)
         node.setnetworkactive(True)

test/functional/test_framework/messages.py

@@ -327,7 +327,7 @@ class CAddress:
         elif self.net == self.NET_CJDNS:
             self.ip = socket.inet_ntop(socket.AF_INET6, addr_bytes)
         else:
-            raise Exception(f"Address type not supported")
+            raise Exception("Address type not supported")
 
         self.port = int.from_bytes(f.read(2), "big")
 
@@ -354,7 +354,7 @@ class CAddress:
         elif self.net == self.NET_CJDNS:
             r += socket.inet_pton(socket.AF_INET6, self.ip)
         else:
-            raise Exception(f"Address type not supported")
+            raise Exception("Address type not supported")
         r += self.port.to_bytes(2, "big")
         return r
 

test/functional/test_framework/socks5.py

@@ -195,7 +195,7 @@ class Socks5Connection():
             if not self.serv.keep_alive:
                 self.conn.close()
             else:
-                logger.debug(f"Keeping client connection alive")
+                logger.debug("Keeping client connection alive")
 
 class Socks5Server():
     def __init__(self, conf):

test/functional/wallet_backup.py

@@ -157,7 +157,7 @@ class WalletBackupTest(BitcoinTestFramework):
         node.pruneblockchain(250)
         # The backup should be updated with the latest height (locator) for
         # the backup to load successfully this close to the prune height
-        node.restorewallet(f'pruned', node.datadir_path / 'wallet_pruned.bak')
+        node.restorewallet('pruned', node.datadir_path / 'wallet_pruned.bak')
 
     def run_test(self):
         self.log.info("Generating initial blockchain")

test/functional/wallet_fast_rescan.py

@@ -49,7 +49,7 @@ class WalletFastRescanTest(BitcoinTestFramework):
         assert_equal(len(descriptors), NUM_DESCRIPTORS)
         w.backupwallet(WALLET_BACKUP_FILENAME)
 
-        self.log.info(f"Create txs sending to end range address of each descriptor, triggering top-ups")
+        self.log.info("Create txs sending to end range address of each descriptor, triggering top-ups")
         for i in range(NUM_BLOCKS):
             self.log.info(f"Block {i+1}/{NUM_BLOCKS}")
             for desc_info in w.listdescriptors()['descriptors']:

test/functional/wallet_multisig_descriptor_psbt.py

@@ -53,8 +53,8 @@ class WalletMultisigDescriptorPSBTTest(BitcoinTestFramework):
         for i, node in enumerate(self.nodes):
             node.createwallet(wallet_name=f"{self.name}_{i}", blank=True, descriptors=True, disable_private_keys=True)
             multisig = node.get_wallet_rpc(f"{self.name}_{i}")
-            external = multisig.getdescriptorinfo(f"wsh(sortedmulti({self.M},{f','.join(external_xpubs)}))")
-            internal = multisig.getdescriptorinfo(f"wsh(sortedmulti({self.M},{f','.join(internal_xpubs)}))")
+            external = multisig.getdescriptorinfo(f"wsh(sortedmulti({self.M},{','.join(external_xpubs)}))")
+            internal = multisig.getdescriptorinfo(f"wsh(sortedmulti({self.M},{','.join(internal_xpubs)}))")
             result = multisig.importdescriptors([
                 {  # receiving addresses (internal: False)
                     "desc": external["descriptor"],

test/lint/test_runner/src/main.rs

@@ -226,6 +226,7 @@ fn lint_py_lint() -> LintResult {
             "F405", // foo_function may be undefined, or defined from star imports: bar_module
             "F406", // "from module import *" only allowed at module level
             "F407", // an undefined __future__ feature name was imported
+            "F541", // f-string without any placeholders
             "F601", // dictionary key name repeated with different values
             "F602", // dictionary key variable name repeated with different values
             "F621", // too many expressions in an assignment with star-unpacking