python - group_by 返回重复的键

Question

Python 3.6 我有一个简单的对象列表:

for obj in obj_ts:
    print(obj['address'])

这告诉我:

mwpJCSEEkphA1utQGA2Y9Vx8cufv85CgpR
mwpJCSEEkphA1utQGA2Y9Vx8cufv85CgpR
mwpJCSEEkphA1utQGA2Y9Vx8cufv85CgpR
mwpJCSEEkphA1utQGA2Y9Vx8cufv85CgpR
mwpJCSEEkphA1utQGA2Y9Vx8cufv85CgpR
mwpJCSEEkphA1utQGA2Y9Vx8cufv85CgpR
mwpJCSEEkphA1utQGA2Y9Vx8cufv85CgpR
mhRhCZBUP1BsrL6xuXSeAeCNnXcoBHWKAB
mwpJCSEEkphA1utQGA2Y9Vx8cufv85CgpR
mwpJCSEEkphA1utQGA2Y9Vx8cufv85CgpR
mwpJCSEEkphA1utQGA2Y9Vx8cufv85CgpR
mwpJCSEEkphA1utQGA2Y9Vx8cufv85CgpR

然后我想按这些对象进行分组:

for address, t_list in itertools.groupby(obj_ts, key=lambda obj: obj['address']):
    print(address)

但是我得到了 3 个组，而不是 2 个。

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mhRhCZBUP1BsrL6xuXSeAeCNnXcoBHWKAB
mwpJCSEEkphA1utQGA2Y9Vx8cufv85CgpR

Answer 1

评论中的解决方案:

As mentioned in the 1st paragraph of the groupby docs, you need to sort the data (with the same key function) before passing it to groupby

https://docs.python.org/3/library/itertools.html#itertools.groupby