def create_person(firstname, surname, person_number):
    return {
        "firstname": firstname,
        "surname": surname,
        "person_number": person_number
    }

def show_person_simple(persons, person_number):
    for person in persons:
        if person["person_number"] == person_number:
            print(person)

def show_person_filter(persons, person_number=None, firstname=None, surname=None):
    for person in persons:
        good = True
        if person_number is not None and person["person_number"] != person_number:
            good = False
        if firstname is not None and person["firstname"] != firstname:
            good = False
        if surname is not None and person["surname"] != surname:
            good = False
        if good:
            print(person)

# create two persons
p1 = create_person("Leonard", "Bruns", "12345")
p2 = create_person("Paul", "Muller", "41231")

# create list of persons
persons = [p1, p2]
persons.append(create_person("Anna", "Eriksson", "12311"))
persons.append(create_person("Anna", "Muller", "3123"))

# print persons based on person number
show_person_simple(persons, "12345")
# print all persons with firstname Anna
show_person_filter(persons, firstname="Anna")