--- a/contrib/python3-ratchet.py	Sat Oct 05 10:29:34 2019 -0400
+++ b/contrib/python3-ratchet.py	Sun Oct 06 09:45:02 2019 -0400
@@ -25,65 +25,103 @@
 import sys
 
 _hgenv = dict(os.environ)
-_hgenv.update({
-    'HGPLAIN': '1',
-    })
+_hgenv.update(
+    {'HGPLAIN': '1',}
+)
 
 _HG_FIRST_CHANGE = '9117c6561b0bd7792fa13b50d28239d51b78e51f'
 
+
 def _runhg(*args):
     return subprocess.check_output(args, env=_hgenv)
 
+
 def _is_hg_repo(path):
-    return _runhg('hg', 'log', '-R', path,
-                  '-r0', '--template={node}').strip() == _HG_FIRST_CHANGE
+    return (
+        _runhg('hg', 'log', '-R', path, '-r0', '--template={node}').strip()
+        == _HG_FIRST_CHANGE
+    )
+
 
 def _py3default():
     if sys.version_info[0] >= 3:
         return sys.executable
     return 'python3'
 
+
 def main(argv=()):
     p = argparse.ArgumentParser()
-    p.add_argument('--working-tests',
-                   help='List of tests that already work in Python 3.')
-    p.add_argument('--commit-to-repo',
-                   help='If set, commit newly fixed tests to the given repo')
-    p.add_argument('-j', default=os.sysconf(r'SC_NPROCESSORS_ONLN'), type=int,
-                   help='Number of parallel tests to run.')
-    p.add_argument('--python3', default=_py3default(),
-                   help='python3 interpreter to use for test run')
-    p.add_argument('--commit-user',
-                   default='python3-ratchet@mercurial-scm.org',
-                   help='Username to specify when committing to a repo.')
+    p.add_argument(
+        '--working-tests', help='List of tests that already work in Python 3.'
+    )
+    p.add_argument(
+        '--commit-to-repo',
+        help='If set, commit newly fixed tests to the given repo',
+    )
+    p.add_argument(
+        '-j',
+        default=os.sysconf(r'SC_NPROCESSORS_ONLN'),
+        type=int,
+        help='Number of parallel tests to run.',
+    )
+    p.add_argument(
+        '--python3',
+        default=_py3default(),
+        help='python3 interpreter to use for test run',
+    )
+    p.add_argument(
+        '--commit-user',
+        default='python3-ratchet@mercurial-scm.org',
+        help='Username to specify when committing to a repo.',
+    )
     opts = p.parse_args(argv)
     if opts.commit_to_repo:
         if not _is_hg_repo(opts.commit_to_repo):
             print('abort: specified repository is not the hg repository')
             sys.exit(1)
     if not opts.working_tests or not os.path.isfile(opts.working_tests):
-        print('abort: --working-tests must exist and be a file (got %r)' %
-              opts.working_tests)
+        print(
+            'abort: --working-tests must exist and be a file (got %r)'
+            % opts.working_tests
+        )
         sys.exit(1)
     elif opts.commit_to_repo:
         root = _runhg('hg', 'root').strip()
         if not opts.working_tests.startswith(root):
-            print('abort: if --commit-to-repo is given, '
-                  '--working-tests must be from that repo')
+            print(
+                'abort: if --commit-to-repo is given, '
+                '--working-tests must be from that repo'
+            )
             sys.exit(1)
     try:
-        subprocess.check_call([opts.python3, '-c',
-                               'import sys ; '
-                               'assert ((3, 5) <= sys.version_info < (3, 6) '
-                               'or sys.version_info >= (3, 6, 2))'])
+        subprocess.check_call(
+            [
+                opts.python3,
+                '-c',
+                'import sys ; '
+                'assert ((3, 5) <= sys.version_info < (3, 6) '
+                'or sys.version_info >= (3, 6, 2))',
+            ]
+        )
     except subprocess.CalledProcessError:
-        print('warning: Python 3.6.0 and 3.6.1 have '
-              'a bug which breaks Mercurial')
+        print(
+            'warning: Python 3.6.0 and 3.6.1 have '
+            'a bug which breaks Mercurial'
+        )
         print('(see https://bugs.python.org/issue29714 for details)')
         sys.exit(1)
 
-    rt = subprocess.Popen([opts.python3, 'run-tests.py', '-j', str(opts.j),
-                           '--blacklist', opts.working_tests, '--json'])
+    rt = subprocess.Popen(
+        [
+            opts.python3,
+            'run-tests.py',
+            '-j',
+            str(opts.j),
+            '--blacklist',
+            opts.working_tests,
+            '--json',
+        ]
+    )
     rt.wait()
     with open('report.json') as f:
         data = f.read()
@@ -104,12 +142,20 @@
             with open(opts.working_tests, 'w') as f:
                 for p in sorted(oldpass | newpass):
                     f.write('%s\n' % p)
-            _runhg('hg', 'commit', '-R', opts.commit_to_repo,
-                   '--user', opts.commit_user,
-                   '--message', 'python3: expand list of passing tests')
+            _runhg(
+                'hg',
+                'commit',
+                '-R',
+                opts.commit_to_repo,
+                '--user',
+                opts.commit_user,
+                '--message',
+                'python3: expand list of passing tests',
+            )
         else:
             print('Newly passing tests:', '\n'.join(sorted(newpass)))
             sys.exit(2)
 
+
 if __name__ == '__main__':
     main(sys.argv[1:])