def unflatten(master):
result = {}<EOL>for k, v in master.items():<EOL><INDENT>*first, last = k.split('<STR_LIT:.>')<EOL>r = result<EOL>for i in first:<EOL><INDENT>r = r.setdefault(i, {})<EOL><DEDENT>r[last] = v<EOL><DEDENT>return result<EOL>
:param dict master: a multilevel dictionary
:return: a unflattened dictionary
:rtype: dict

Unflattens a single-level dictionary a multilevel into one so that::

    {'foo.bar.a': 1,
     'foo.bar.b': True,
     'foo.bar.a': 1,
     }

would become::

    {'foo':
        {'bar':
           {
               'a': 1,
               'b': True,
               'c': 'hello',
            },
        },
    }