How do you find the intersection of multiple lists in python?
for 2.4, you can just define an intersection function. Show
for newer versions of python: the intersection method takes an arbitrary amount of arguments
alternatively, you can intersect the first set with itself to avoid slicing the list and making a copy:
I'm not really sure which would be more efficient and have a feeling that it would depend on the size of the
in the intersection method. Given two list of lists, write a Python program to find the intersection between the given two lists. Examples: Input : lst1 = [['a', 'c'], ['d', 'e']] lst2 = [['a', 'c'], ['e', 'f'], ['d', 'e']] Output : [['a', 'c'], ['d', 'e']] Input : lst1 = [[1, 5, 7], [2, 3], [6, 9], [4, 8]] lst2 = [[9, 3], [2, 3], [6, 9]] Output : [[2, 3], [6, 9]] The brute-force or naive approach to find the intersection of list of lists is to use List comprehension or simply a for loop.
Output: [['a', 'c'], ['d', 'e']] This is an efficient method in comparison to the naive approach. We first convert both list of lists into list of tuples using map() because Python sets are compatible with tuples, not lists. Then we simply find Set intersection() of both the lists.
Output: [['d', 'e'], ['a', 'c']] Intersection of two list means we need to take all those elements which are common to both of the initial lists and store them into another list. Now there are various ways in Python, through which we can perform the Intersection of the lists. Input : lst1 = [15, 9, 10, 56, 23, 78, 5, 4, 9] lst2 = [9, 4, 5, 36, 47, 26, 10, 45, 87] Output : [9, 10, 4, 5] Input : lst1 = [4, 9, 1, 17, 11, 26, 28, 54, 69] lst2 = [9, 9, 74, 21, 45, 11, 63, 28, 26] Output : [9, 11, 26, 28] Method 1: Python3
Output: [9, 11, 26, 28] Method 2: Python3
Output: [9, 10, 4, 5] Method 3: Python3
Output: {9, 11} Method 4: Python3
Output: [9, 9, 11] Method 5: Python3
Working: The filter part takes each sublist’s item and checks to see if it is in the source list. The list comprehension is executed for each sublist in list2. [[13, 32], [7, 13, 28], [1, 6]] How do you find the intersection of multiple sets in Python?To intersect multiple sets, stored in a list l , use the Python one-liner l. pop(). intersection(*l) that takes the first set from the list, calls the intersection() method on it, and passes the remaining sets as arguments by unpacking them from the list.
How do you intersect multiple lists?Iterate over the first list and add the current item in the new list if it presents in the second list as well.. Convert two lists items into tuples using map.. Intersect two sets using intersection and map method.. Convert the result to list.. Print the result.. How do you find the intersection of three lists in Python?Each list is iterated once to create the sets, and then the sets are intersected. The naive way to solve this using a filtered list comprehension as Geotob did will iterate lists b and c for each element of a , so for longer list, this will be a lot less efficient. Show activity on this post.
How do you find the intersection in Python?How to Find the Intersection of Sets in Python?. 1) Using intersection() function.. 2) Using intersection operator(&). 3) Using empty set for set intersection.. |