diff --git a/pkg_resources/__init__.py b/pkg_resources/__init__.py
index a7eaee30930..b37b2abe950 100644
--- a/pkg_resources/__init__.py
+++ b/pkg_resources/__init__.py
@@ -199,7 +199,8 @@ def get_supported_platform():
     m = macosVersionString.match(plat)
     if m is not None and sys.platform == "darwin":
         try:
-            plat = 'macosx-{}-{}'.format('.'.join(_macos_vers()[:2]), m.group(3))
+            major_minor = '.'.join(_macos_vers()[:2])
+            plat = f'macosx-{major_minor}-{m.group(3)}'
         except ValueError:
             # not macOS
             pass
@@ -2557,7 +2558,8 @@ def __str__(self):
         if self.attrs:
             s += ':' + '.'.join(self.attrs)
         if self.extras:
-            s += ' [{}]'.format(','.join(self.extras))
+            extras = ','.join(self.extras)
+            s += f' [{extras}]'
         return s
 
     def __repr__(self):
diff --git a/setuptools/_core_metadata.py b/setuptools/_core_metadata.py
index 86eef673fa1..2cbdb71807a 100644
--- a/setuptools/_core_metadata.py
+++ b/setuptools/_core_metadata.py
@@ -176,8 +176,8 @@ def write_field(key, value):
     if license:
         write_field('License', rfc822_escape(license))
 
-    for project_url in self.project_urls.items():
-        write_field('Project-URL', '{}, {}'.format(*project_url))
+    for label, url in self.project_urls.items():
+        write_field('Project-URL', f'{label}, {url}')
 
     keywords = ','.join(self.get_keywords())
     if keywords:
diff --git a/setuptools/command/easy_install.py b/setuptools/command/easy_install.py
index 06d28069134..f3ff897b823 100644
--- a/setuptools/command/easy_install.py
+++ b/setuptools/command/easy_install.py
@@ -1021,7 +1021,8 @@ def install_exe(self, dist_filename, tmpdir):
                 f.write('Metadata-Version: 1.0\n')
                 for k, v in cfg.items('metadata'):
                     if k != 'target_version':
-                        f.write('{}: {}\n'.format(k.replace('_', '-').title(), v))
+                        k = k.replace('_', '-').title()
+                        f.write(f'{k}: {v}\n'
         script_dir = os.path.join(_egg_info, 'scripts')
         # delete entry-point scripts to avoid duping
         self.delete_blockers([
diff --git a/setuptools/tests/config/test_setupcfg.py b/setuptools/tests/config/test_setupcfg.py
index 6b6e347da86..0b9c7bf0082 100644
--- a/setuptools/tests/config/test_setupcfg.py
+++ b/setuptools/tests/config/test_setupcfg.py
@@ -92,7 +92,7 @@ def test_basic(self, tmpdir):
 
     def test_no_config(self, tmpdir):
         with pytest.raises(DistutilsFileError):
-            read_configuration('{}'.format(tmpdir.join('setup.cfg')))
+            read_configuration(str(tmpdir.join('setup.cfg')))
 
     def test_ignore_errors(self, tmpdir):
         _, config = fake_env(
@@ -100,9 +100,9 @@ def test_ignore_errors(self, tmpdir):
             '[metadata]\n' 'version = attr: none.VERSION\n' 'keywords = one, two\n',
         )
         with pytest.raises(ImportError):
-            read_configuration(f'{config}')
+            read_configuration(str(config))
 
-        config_dict = read_configuration(f'{config}', ignore_option_errors=True)
+        config_dict = read_configuration(str(config), ignore_option_errors=True)
 
         assert config_dict['metadata']['keywords'] == ['one', 'two']
         assert 'version' not in config_dict['metadata']
diff --git a/setuptools/tests/test_build_ext.py b/setuptools/tests/test_build_ext.py
index 6ccd9ebc299..75606f1de2f 100644
--- a/setuptools/tests/test_build_ext.py
+++ b/setuptools/tests/test_build_ext.py
@@ -285,8 +285,8 @@ def test_build_ext_config_handling(tmpdir_cwd):
         ),
     }
     path.build(files)
-    code, output = environment.run_setup_py(
+    code, (stdout, stderr) = environment.run_setup_py(
         cmd=['build'],
         data_stream=(0, 2),
     )
-    assert code == 0, '\nSTDOUT:\n{}\nSTDERR:\n{}'.format(*output)
+    assert code == 0, f'\nSTDOUT:\n{stdout}\nSTDERR:\n{stderr}'