Method upper

crates/vm/src/builtins/str.rs:722–728

(&self)

    #[pymethod]
    fn upper(&self) -> Self {
        match self.as_str_kind() {
            PyKindStr::Ascii(s) => s.to_ascii_uppercase().into(),
            PyKindStr::Utf8(s) => s.to_uppercase().into(),
            PyKindStr::Wtf8(w) => w.to_uppercase().into(),
        }
    }

    #[pymethod]
    fn capitalize(&self) -> Wtf8Buf {