@classmethod
def from_string(cls, string, ctx=None, pwd=None, constructors=None,
    multi_constructors=None, configure=True):
    """ Construct :class:`.Configuration` from ``string``.

        :param string:
            string to parse config from
        :param ctx:
            mapping object used for value interpolation
        :param constructors:
            mapping of names to constructor for custom objects in YAML. Look at
            `_timedelta_constructor` and `_re_constructor` for examples.
        """
    ctx = ctx or {}
    ctx['pwd'] = pwd
    string = string % ctx
    cfg = cls.load(string, constructors=constructors, multi_constructors=
        multi_constructors)
    return cls.from_dict(cfg, pwd=pwd, configure=configure)
