common way to add key value in dictionary python code example

Example 1: add new keys to a dictionary python

d = {'key':'value'}
print(d)
# {'key': 'value'}
d['mynewkey'] = 'mynewvalue'
print(d)
# {'mynewkey': 'mynewvalue', 'key': 'value'}

Example 2: add values to dictionary key python

key = "somekey"
a.setdefault(key, [])
a[key].append(2)