test: use f-strings in feature_asmap.py

Author: fanquake

test/functional/feature_asmap.py

@@ -31,8 +31,8 @@
 VERSION = 'fec61fa21a9f46f3b17bdcd660d7f4cd90b966aad3aec593c99b35f0aca15853'
 
 def expected_messages(filename):
-    return ['Opened asmap file "{}" (59 bytes) from disk'.format(filename),
-            'Using asmap version {} for IP bucketing'.format(VERSION)]
+    return [f'Opened asmap file "{filename}" (59 bytes) from disk',
+            f'Using asmap version {VERSION} for IP bucketing']
 
 class AsmapTest(BitcoinTestFramework):
     def set_test_params(self):
@@ -50,7 +50,7 @@ def test_asmap_with_absolute_path(self):
         filename = os.path.join(self.datadir, 'my-map-file.map')
         shutil.copyfile(self.asmap_raw, filename)
         with self.node.assert_debug_log(expected_messages(filename)):
-            self.start_node(0, ['-asmap={}'.format(filename)])
+            self.start_node(0, [f'-asmap={filename}'])
         os.remove(filename)
 
     def test_asmap_with_relative_path(self):
@@ -60,13 +60,13 @@ def test_asmap_with_relative_path(self):
         filename = os.path.join(self.datadir, name)
         shutil.copyfile(self.asmap_raw, filename)
         with self.node.assert_debug_log(expected_messages(filename)):
-            self.start_node(0, ['-asmap={}'.format(name)])
+            self.start_node(0, [f'-asmap={name}'])
         os.remove(filename)
 
     def test_default_asmap(self):
         shutil.copyfile(self.asmap_raw, self.default_asmap)
         for arg in ['-asmap', '-asmap=']:
-            self.log.info('Test bitcoind {} (using default map file)'.format(arg))
+            self.log.info(f'Test bitcoind {arg} (using default map file)')
             self.stop_node(0)
             with self.node.assert_debug_log(expected_messages(self.default_asmap)):
                 self.start_node(0, [arg])
@@ -75,15 +75,15 @@ def test_default_asmap(self):
     def test_default_asmap_with_missing_file(self):
         self.log.info('Test bitcoind -asmap with missing default map file')
         self.stop_node(0)
-        msg = "Error: Could not find asmap file \"{}\"".format(self.default_asmap)
+        msg = f"Error: Could not find asmap file \"{self.default_asmap}\""
         self.node.assert_start_raises_init_error(extra_args=['-asmap'], expected_msg=msg)
 
     def test_empty_asmap(self):
         self.log.info('Test bitcoind -asmap with empty map file')
         self.stop_node(0)
         with open(self.default_asmap, "w", encoding="utf-8") as f:
             f.write("")
-        msg = "Error: Could not parse asmap file \"{}\"".format(self.default_asmap)
+        msg = f"Error: Could not parse asmap file \"{self.default_asmap}\""
         self.node.assert_start_raises_init_error(extra_args=['-asmap'], expected_msg=msg)
         os.remove(self.default_asmap)