def load(self, requirements_file=None):
        """Load or reload requirements from a requirements.txt file.

        :param requirements_file: if not given, the filename used from
            initialization will be read again.
        """
        if requirements_file is None:
            requirements_file = self.filename
            if requirements_file is None:
                raise ValueError("no filename provided")
        elif isinstance(requirements_file, text_type):
            requirements_file = Path(requirements_file)
        self.clear()
        with requirements_file.open() as f:
            self.loads(f.read())

        if isinstance(requirements_file, (text_type, Path)):
            self.filename = requirements_file
def test_urls():
    urls = [
        'http://www.djangoproject.com/',
        'http://localhost/',
        'http://example.com/',
        'http://www.example.com/',
        'http://www.example.com:8000/test',
        'http://valid-with-hyphens.com/',
        'http://subdomain.example.com/',
        'http://200.8.9.10/',
        'http://200.8.9.10:8000/test',
        'http://valid-----hyphens.com/',
        'http://example.com?something=value',
        'http://example.com/index.php?something=value&another=value2',
        'http://foo:bar@example.com',
        'http://foo:@example.com',
        'http://foo:@2001:db8:85a3::8a2e:370:7334',
        'http://foo2:qd1%r@example.com',
    ]

    for value in urls:
        yield assert_equal, inputs.url(value), value