Elegant pattern for mutually exclusive keyword args?

How about using something like a command dispatch pattern:

def funct(objnameOrType):
   dispatcher = {str: getObjByName,
                 type1: getObjByType1,
                 type2: getObjByType2}
   t = type(objnameOrType)
   obj = dispatcher[t](objnameOrType)
   doStuffWithObj(obj)

where type1,type2, etc are actual python types (e.g. int, float, etc).

Sounds like it should go to https://codereview.stackexchange.com/

Anyway, keeping the same interface, I may try

arg_parsers = {
  'objname': getObjByName,
  'objtype': getObjByType,
  ...
}
def func(**kwargs):
  assert len(kwargs) == 1 # replace this with your favorite exception
  (argtypename, argval) = next(kwargs.items())
  obj = arg_parsers[argtypename](argval) 
  doStuffWithObj(obj)

or simply create 2 functions?

def funcByName(name): ...
def funcByType(type_): ...