How do I print the unique list elements between two lists in Python (aka. how to print the items not in both lists)

Question

Write a function that takes two lists as parameters. Your function should check if an element is in both lists. After checking all elements, your function should print the following:

These items are in both lists: (elements that are in both lists) I got this one right

These items are not in both lists: (elements that are not in both lists) This is the one I need help with

For example, given

listOne = ["a", "b", "c", "d"] and listTwo = ["c", "d", "e", "f"]

your function would print

These items are in both lists: c d These items are not in both lists: abef

use the following function header:

def checkItemsInList(listOne, listTwo):

Below is the code I ended up with, for the items in both lists I got that part right, but for the part that asks for items that are not in both lists, I get the wrong output of ['b', 'a'] , when I need ['a','b','e','f'] .

INPUT
    def checkItemsInList(listOne, listTwo):
        listOne = ["a", "b", "c", "d"]
        listTwo = ["c", "d", "e", "f"]

# for the items in both lists
print(list(set(listOne) & set(listTwo)))
# for the items not in both lists
list(set(listOne) - set(listTwo))

OUTPUT
['d', 'c']
['b', 'a']

Answer 1

You can use function symmetric_difference

>>> set(listOne).symmetric_difference(listTwo)
{'b', 'f', 'e', 'a'}

Answer 2

You didn't check for items that exist in list_b but not in list_a (you checked only the opposite direction):

in_both = list(set(listOne) & set(listTwo))
# for the items not in both lists
not_in_both = list(set(listOne) - set(listTwo)) + list(set(listTwo) - set(listOne))

or

not_in_both = list(set(listOne+listTwo)-set(in_both))

Answer 3

Check this if it works

def checkItemsInList(listOne, listTwo):
    res = []
    for i in listOne:
        if i in listTwo:
            res.append(i)
    print(res)

For remaining elements, you can use

list(set(listOne) ^ set(listTwo))

Answer 4

Or you could try this list comprehension approach:

listOne = ["a", "b", "c", "d"]
listTwo = ["c", "d", "e", "f"]

def checkItemsInList(firstl, secondl):

  comm = [ x for x in firstl if x in secondl]
  uniq = [ j for j in firstl+secondl if j not in comm]

  print('Elements in both : ', comm)
  print('Elements not in both: ', uniq)

checkItemsInList(listOne,listTwo)

Output:

Elements in both :  ['c', 'd']
Elements not in both:  ['a', 'b', 'e', 'f']