我如何更改包含元組數據的列表，以復制已刪除元組的列表

Question

我的清單是這樣的

list = [('N',''),('N',''),('K','asdf'),('K','asw'),('S','aqq'),('N',''),('N',''),('N','')]

我想將此列表更改為

list_1 = [('N',''),('K','asdf'),('K','asdf'),('S','aqq'),('N','')]

僅應刪除重復的N。

Answer 1

您可以使用itertools.groupby並使用next來獲取每個組中的第一項。

>>> import itertools
>>> l = [('N',''),('N',''),('K','asdf'),('K','asw'),('S','aqq'),('N',''),('N',''),('N','')]
>>> [next(group) for key, group in itertools.groupby(l)]
[('N', ''), ('K', 'asdf'), ('K', 'asw'), ('S', 'aqq'), ('N', '')]

編輯 ：
如果您只想刪除以'N'開頭的元組的連續重復項，則可以使用

>>> [key if key[0] == 'N' else list(itertools.chain.from_iterable(group)) for key, group in itertools.groupby(l)]
[('N', ''), ['K', 'asdf'], ['K', 'asw'], ['S', 'aqq'], ('N', '')]

Answer 2

只需使用set即可刪除重復項

>>> old_list
[('N', ''), ('N', ''), ('K', 'asdf'), ('K', 'asw'), ('S', 'aqq'), ('N', ''), ('N', ''), ('N', '')]
>>> list_1 = list((set(old_list)))
>>> list_1
[('K', 'asdf'), ('N', ''), ('K', 'asw'), ('S', 'aqq')]