Method setdefault

tools/python-3.11.9-amd64/Lib/os.py:716–719

(self, key, value)

        return dict(self)

    def setdefault(self, key, value):
        if key not in self:
            self[key] = value
        return self[key]

    def __ior__(self, other):
        self.update(other)