Get the intersection from a single nested list?

Question

I have the following nested list:

list_ = [['The'], ['The', 'fox', 'quick'], ['quick', 'the'], ['dog']]

How can I compute efficiently the intersection between each sublist?:

['the', 'quick']

I tried to:

list(itertools.product([for e in [list_]]))

Answer 1

First, preprocess your list to make all words lower-case:

list_ = [set(word.lower() for word in item) for item in list_]

Then you want to use itertools.combinations and the set() operations:

results = [x&y for x,y in itertools.combinations(list_,2)]
# [{'the'}, {'the'}, set(), {'the', 'quick'}, set(), set()]