# dict declaration
empty_dict = dict()
another_empty_dict = {}

people = {
    "masoud": {'position': 'teacher', 'age': 21},
    "hasan": {'position': 'student', 'age': 22},
    "taghi": {'position': 'programmer', 'age': 23},
    "asghar": {'position': 'artist', 'age': 24}
}
people["masoud"]['phone'] = '09121231231'

print(list(people.keys()))
print(list(people.values()))

for person_k, person_v in people.items():
    print(person_k, '->', person_v)