from collections import defaultdict

user = defaultdict(lambda: 'Kevin')

user

defaultdict(<function __main__.<lambda>()>, {})

type(user)

collections.defaultdict

user['abc']

'Kevin'

user['name'] = 'Peter'
user['age'] = 21
user['city'] = 'Toronto'

user

defaultdict(<function __main__.<lambda>()>,
            {'abc': 'Kevin', 'name': 'Peter', 'age': 21, 'city': 'Toronto'})

defaultdict(<function __main__.<lambda>>,
            {'abc': 'Kevin',
             'age': 21,
             'city': 'Toronto',
             'country': 'Kevin',
             'name': 'Peter'})

  Cell In[8], line 1
    defaultdict(<function __main__.<lambda>>,
                ^
SyntaxError: invalid syntax

from collections import defaultdict

d = defaultdict(lambda: 'default value', {
    'abc': 'Kevin',
    'age': 21,
    'city': 'Toronto',
    'country': 'Kevin',
    'name': 'Peter'
})

for k, v in user.items():
    print(k, "==>", v)

abc ==> Kevin
name ==> Peter
age ==> 21
city ==> Toronto