def is_generator_function(obj):
  CO_GENERATOR = 0x20
  return bool(((inspect.isfunction(obj) or inspect.ismethod(obj)) and
               obj.func_code.co_flags & CO_GENERATOR))
Return true if the object is a user-defined generator function.
dataset/ETHPy150Open livid/v2ex/mapreduce/util.py/is_generator_function