How to get a pytest progress bar in xterm title

conftest.py

# Put this in your top-level conftest.py

class XTermProgress:

    def __init__(self, stdout=sys.stdout):
        self.init(stdout)
        self.session = None
        self.reported = set()
        self.args = []

    def init(self, stdout):
        self.stdout = stdout
        self.enabled = os.environ.get('TERM', '').startswith('xterm') and stdout.isatty()

    def ready(self, session):
        self.session = session

    def set_args(self, args):
        self.args = list(args)

    @property
    def finished_tests(self):
        return len(self.reported)

    @property
    def total_tests(self):
        return self.session.testscollected

    @property
    def progress(self):
        if self.total_tests == 0:
            return '0%'
        else:
            return f'{100 * self.finished_tests / self.total_tests:.1f}%'

    def logreport(self, report):
        if self.enabled:
            self.reported.add(report.nodeid)
            message = f"{self.progress} - {' '.join(['pytest'] + self.args)}"
            self.stdout.write(f"\033]0;{message}\a")
            self.stdout.flush()


TERMINAL_PROGRESS = XTermProgress()


@pytest.mark.trylast
def pytest_configure(config):
    standard_reporter = config.pluginmanager.getplugin('terminalreporter')
    if hasattr(getattr(standard_reporter, '_tw', None), '_file'):
        # XXX: I was unable to find a blessed way of getting the real stdout
        # stream from pytest APIs, and I can't use standard_reporter.write() because
        # it sprinkles extraneous newlines everywhere!
        TERMINAL_PROGRESS.init(standard_reporter._tw._file)
    if hasattr(config, 'invocation_params'):  # pytest 5.1 required
        TERMINAL_PROGRESS.set_args(config.invocation_params.args)


def pytest_collection(session):
    TERMINAL_PROGRESS.ready(session)


def pytest_runtest_logreport(report):
    TERMINAL_PROGRESS.logreport(report)