What is your evidence for this claim? So far I've only seen one real-
world use-case for this, and that single use-case would be well served
by a simpler syntax:
a, b, c = **mapping
which just requires that a, b, c etc are legal names (not general
identifiers). The dict is then unpacked:
a = mapping['a']
a, b, c = (mapping[x] for x in ['a','b','c'])
x, y, z = (2*mapping[x] for x in get_keys() if x.isupper())