You might want: foo = mapping.pop("foo", "default") It removes "foo" key from mapping if any. `foo` is "default" if "foo" is missing and `mapping["foo"]`

You might want: foo = mapping.pop("foo", "default") It removes "foo" key from mapping if any. `foo` is "default" if "foo" is missing and `mapping["foo"]` otherwise. Dictionary unpacking compatible with the match/case syntax could look like: {"foo": foo, **rest} = mapping It asserts that there is "foo" key in mapping and puts its value into `foo`.