3.8. Match Mapping

A mapping pattern looks like {"user": u, "emails": [*es]}. It matches mappings with at least the set of provided keys, and if all the sub-patterns match their corresponding values. It binds whatever the sub-patterns bind while matching with the values corresponding to the keys. Adding **rest at the end of the pattern to capture extra items is allowed.


>>> def login_user(firstname, lastname): ...
>>> def login_admin(firstname, lastname): ...


>>> user = {'role': 'admin', 'firstname': 'Mark', 'lastname': 'Watney'}
>>> match user:
...     case {'role': 'admin', 'firstname': firstname, 'lastname': lastname}:
...         login_admin(firstname, lastname)
...     case {'role': 'user', 'firstname': firstname, 'lastname': lastname}:
...         login_user(firstname, lastname)

3.8.1. Args, Kwargs

>>> user = {'role': 'admin', 'firstname': 'Mark', 'lastname': 'Watney'}
>>> match user:
...     case {'role': 'admin', **data}:  login_admin(**data)
...     case {'role': 'user', **data}:   login_user(**data)

3.8.2. Assignments