Нужно исправить программу (Вечеринка)

name = ''
ll = []
 
 
def add_friends(name_of_person, list_of_friends):
    global name
    global ll
    if name_of_person not in name:
        name += name_of_person
        ll.extend([[name_of_person],[list_of_friends]])
    else:
        for i in ll:
            if i[0] == name_of_person:
                i[1] += list_of_friends
 
 
def are_friends(name_of_person1, name_of_person2):
    global name
    global ll
    if name_of_person1 in name and name_of_person2 in ll:
        return True
    return False
 
 
def print_friends(name_of_person):
    global name
    global ll
    print(ll)

dict = {}
 
 
def add_friends(name_of_person, list_of_friends):
    dict[name_of_person] = list_of_friends
 
 
def are_friends(name_of_person1, name_of_person2):
    if name_of_person2 in dict[name_of_person1]:
        return True
    return False
 
 
def print_friends(name_of_person):
    for i in dict[name_of_person]:
        print(i, end=' ')
    print()

add_friends("Катя", ["Женя", "Даша"])
print(are_friends("Катя", "Филипп"))
add_friends("Катя", ["Филипп"])
print(are_friends("Катя", "Филипп"))
print(are_friends("Катя", "Даша"))

def add_friends(name_of_person, list_of_friends):
    if name_of_person in friends:
        friends[name_of_person]+=list_of_friends
    else:
        friends[name_of_person] = list_of_friends

persones = {}
 
 
def add_friends(name_of_person, list_of_friends):
    a = persones.get(name_of_person)
    if a:
        persones[name_of_person] = a + list_of_friends
    else:
        persones[name_of_person] = list_of_friends
 
 
def are_friends(name_of_person1, name_of_person2):
    if name_of_person2 in persones[name_of_person1]:
        return True
    return False
 
 
def print_friends(name_of_person):
    s = reversed(persones[name_of_person])
    for i in s:
        print(i, end=' ')
    print()