how can i change my list which contains tuple data, to duplicating tuple removed list

Question

My list is like this

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

I want change this list to

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

only duplicated N should be removed..

Answer 1

You can use itertools.groupby and grab the first item out of each group using next .

>>> 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', '')]

Edit :
If you just want to remove the consecutive duplicates of the tuples starting with 'N' then you can use

>>> [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

simply you can use set to remove duplicates

>>> 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')]