Python Set operations

art_friends = {"Rolf", "Anne", "Jen"}
scrience_friends = {"Jen", "Charlie"}

art_but_not_science = art_friends.difference(science_friends) # {"Anne", "Rolf"}
science_but_not_art = science_friends.difference(art_friends) # {"Charlie"}

not in_both = art_friends.symmetric_difference(scrience_friends)  # {"Anne", "Rolf", "Charlie"}

art_and_science = art_friends.intersection(science_friends) # {"Jen"}

all_friends = art_friends.union(science_friends) # {"Anne", "Jen", "Rolf", "Charlie"}