The mutable #python default args feels like a kilodollar mistake to me.
Not quite as bad as null pointers, but comparably annoying.

@jeeger

It is, but there you go. Luckily linters can protect you from it

@gotofritz Yeah, it's not as much about getting tripped up by it but not being able to use complex objects as default arguments without extra code.

@gotofritz So you can't do something like

`def fun(arg: SomeType = SomeType.default)`, but you have to do `def fun(arg: SomeType | None = None)` and then check for None manually.
Not a big inconvenience, but annoying nonetheless.

@jeeger

ikr, it's irritating!