Difference Between Two Lists

When working with lists in Python, it may become necessary to determine the differences between two lists. There are several effective methods to compute list differences, depending on the specific requirements.

One approach is to utilize set difference, which disregards the order of elements and focuses solely on the unique values. This method is ideal if the order of elements is not crucial.

For instance, given lists A = [1,2,3,4] and B = [2,5], set difference can be calculated as:

set_difference = set(A) - set(B)
print(set_difference)  # Output: {1, 4, 3}

This computation yields a set containing the unique elements in A that are not present in B. Similarly, to find the unique elements in B, use:

set_difference = set(B) - set(A)
print(set_difference)  # Output: {5}