person = {'name': 'Phill', 'age': 22}

age = person.setdefault('age')
print('person = ',person)
print('Age = ',age)

#############


person = {'name': 'Phill'}

# key is not in the dictionary
salary = person.setdefault('salary')
print('person = ',person)
print('salary = ',salary)

# key is not in the dictionary
# default_value is provided
age = person.setdefault('age', 22)
print('person = ',person)
print('age = ',age)