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 items(self, section_name):
            if section_name != section:
                raise NoSectionError(section_name)
            return {
                'memcache_servers': memcache_servers,
                'memcache_serialization_support':
                memcache_serialization_support,
                'memcache_max_connections': memcache_max_connections,
            }