def __init__(self, package, version):
        """Construct a new requirement.

        :param package: the package name.
        :param version: a semver compatible version specification.
        """
        self.package = package
        self.version = version
        if self.version and not re.match(r"[<=>~]", version[:2]):
            self.version = "=={}".format(self.version)
def test_keyword_initializers(self):
        class POINT(Structure):
            _fields_ = [("x", c_int), ("y", c_int)]
        pt = POINT(1, 2)
        self.assertEqual((pt.x, pt.y), (1, 2))

        pt = POINT(y=2, x=1)
        self.assertEqual((pt.x, pt.y), (1, 2))