[ul5255]

minor nit: it will not even reach the yield expression because it fails to resolve g:

  >>> import dis
  >>> f = lambda: g((yield))
  >>> dis.dis(f)
    1           0 LOAD_GLOBAL              0 (g)
                3 LOAD_CONST               0 (None)
                6 YIELD_VALUE
                7 CALL_FUNCTION            1
               10 RETURN_VALUE
  >>>