Quick demonstration of `__slots__` with inheritance. Subclasses are able to make their own independent decision on whether to use slots or not. Subclasses will use a dynamic `__dict__` instead of the static `__slots__` as usual, even if their parent class uses `__slots__`.

slots.py

class Foo:
    __slots__ = ["spam", "eggs"]

    def __init__(self) -> None:
        self.spam = "spam"
        self.eggs = "eggs"


class Bar(Foo):
    def __init__(self):
        super().__init__()
        self.bar = "bar"
        self.eggs = "yum"
        self.spam = "gross"


foo = Foo()
bar = Bar()

print(foo.spam, foo.eggs)
# spam eggs

print(bar.spam, bar.eggs, bar.bar)
# gross yum bar

bar.dynamic_attribute = "works"
print(bar.dynamic_attribute)
# works

foo.dynamic_attribute = "doesn't work"