Helpers.parallel_bulk in Python not working?

学习了：https://discuss.elastic.co/t/helpers-parallel-bulk-in-python-not-working/39498

需要写：

parallel bulk is a generator, meaning it is lazy and won't produce any results until you start consuming them. The proper way to use it is:

parallel_bulk是惰性的；

for success, info in parallel_bulk(...):
    if not success:
        print('A document failed:', info)

不这样写真报错呀；

而且必须进行if判断，要不然会输出很多内容；

直接写 a,b = parallel_bulk(...) if not a print(b) 会报一个too many value to unpack 错误；