find common emails from two lists (intersection from two sets)

example.py

import csv


def intersection(list1, list2):
    """
    Find the unique intersection of two lists and return the intersection as a list.
    """
    return [value for value in list1 if value in list2]


if __name__ == "__main__":
    lists = []
    with open('file-name.csv') as csv_file:
        rows = csv.reader(csv_file, delimiter=',')
        for row in rows:  # row looks like a@a.com b@b.com
            lists.append(list(row))  # put row in a list and append to lists

    res_list = intersection(lists[0], lists[1])
    print(res_list)  # print the intersected result list of two lists
    print(len(res_list))  # printing the length of the list tells us 
                          # how many emails are common in two lists