python2.7 - python 2.7中有async for的等价表达方式吗？

Answer 1

Changing it to asynchronous is not of much use. Your situation is very computationally intensive, and your time should be spent on "key in need_cols". need_cols should also be a large array. Just find a way to optimize this area.
Try changing it to this

ind = set(i.keys()) & set(need_cols)
temp = {d: i[d] for d in ind}

Answer 2

Ask and answer your own questions

Just change it to a generator

def data_generator(*args):
    for i in v_data:  # v_data是个较大的dict
        temp = {key: value for key, value in i.iteritems() if key in need_cols}  # 部分key不需要
        temp["sid"] = sid  # 单独加一个sid
        yield temp