python dictionary one key with several values code example

Example 1: python dictionary multiple same keys

No, each key in a dictionary should be unique. 
You can’t have two keys with the same value. 
Attempting to use the same key again will just overwrite the previous value stored. 
If a key needs to store multiple values, 
then the value associated with the key should be a list or another dictionary.
Sourece: https://discuss.codecademy.com/t/can-a-dictionary-have-two-keys-of-the-same-value/351465

Example 2: dictionary multiple values per key

key = "somekey"
a.setdefault(key, [])
a[key].append(1)