python add to set key value code example

Example 1: add values to dictionary key python

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

Example 2: add key to dictionary python

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