Method fromkeys

Lib/collections/__init__.py:1054–1056

Create a new ChainMap with keys from iterable and values set to value.

(cls, iterable, value=None, /)

    @classmethod
    def fromkeys(cls, iterable, value=None, /):
        'Create a new ChainMap with keys from iterable and values set to value.'
        return cls(dict.fromkeys(iterable, value))

    def copy(self):
        'New ChainMap or subclass with a new copy of maps[0] and refs to maps[1:]'