How Can We Efficiently Find the Intersection of Two Lists in Python?

Intersecting Lists: Capturing Overlapping Elements

In this programming riddle, we seek a solution to determine the intersection of two lists, identifying the common elements between them. Given two lists, 'a' and 'b', the task is to find the list that contains only the elements shared by both lists.

Problem Statement: Boolean AND Operation on Lists

Consider the following code snippet:

a = [1,2,3,4,5]
b = [1,3,5,6]
c = a and b
print c

When executing this code, one might anticipate an output of '[1,3,5]' as the intersection of lists 'a' and 'b'. However, the actual output is '[1,3,5,6]', which includes elements not present in the intersection.

Solution: Utilizing Set Intersection

To accomplish a boolean AND operation (list intersection) on the two lists, avoiding duplicates and maintaining order, we can leverage set intersection. Sets are unordered collections of unique elements. By converting the lists into sets, taking their intersection, and converting the resulting set back to a list, we can obtain the desired result:

>>> a = [1,2,3,4,5]
>>> b = [1,3,5,6]
>>> list(set(a) & set(b))
[1, 3, 5]

This solution efficiently identifies and returns only the elements that belong to both lists, providing a concise representation of their intersection.

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