def coerce(cls, string):
        """Create a :class:`Requirement` object from a given package spec."""
        match = re.match(cls.spec_regex, string)
        if not match:
            raise InvalidRequirementSpecError("could not parse requirement")
        package = match.group(1)
        if all(match.group(2, 3)):
            version = "".join(match.group(2, 3))
        else:
            version = None
        return cls(package, version)
def unique_name():
    now_time = datetime.datetime.now().strftime("%Y%m%d%H%M%S")
    random_num = random.randint(0, 100)
    if random_num <= 10:
        random_num = str(0) + str(random_num)
    unique_num = str(now_time) + str(random_num)
    return unique_num