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I am playing with python and am able to get the intersection of two lists:
result = set(a).intersection(b) Now if d is a list containing a and b and a third element c, is there an built-in function for finding the intersection of all the three lists inside d? So for instance,
d = [[1,2,3,4], [2,3,4], [3,4,5,6,7]] then the result should be
[3,4] 
869
You can concatenate multiple lists into one list by using the * operator. For Example, [*list1, *list2] – concatenates the items in list1 and list2 and creates a new resultant list object. Usecase: You can use this method when you want to concatenate multiple lists into a single list in one shot.
You can simply use a for loop to create n lists. The variable a_i changes as i increments, so it becomes a_1, a_2, a_3 ... and so on. Show activity on this post. there is a way to do that if you want to create variables.
set.intersection(*map(set,d)) for 2.4, you can just define an intersection function.
def intersect(*d): sets = iter(map(set, d)) result = sets.next() for s in sets: result = result.intersection(s) return result for newer versions of python:
the intersection method takes an arbitrary amount of arguments
result = set(d[0]).intersection(*d[1:]) alternatively, you can intersect the first set with itself to avoid slicing the list and making a copy:
result = set(d[0]).intersection(*d) I'm not really sure which would be more efficient and have a feeling that it would depend on the size of the d[0] and the size of the list unless python has an inbuilt check for it like
if s1 is s2: return s1 in the intersection method.
>>> d = [[1,2,3,4], [2,3,4], [3,4,5,6,7]] >>> set(d[0]).intersection(*d) set([3, 4]) >>> set(d[0]).intersection(*d[1:]) set([3, 4]) >>> If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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