After values = [parsed for raw in rows if (parsed := parse(raw)) is not None] succeeds, w…

After values = [parsed for raw in rows if (parsed := parse(raw)) is not None] succeeds, where is parsed bound?

1. In the scope containing the comprehension, with the last assigned value
2. Only in the comprehension’s implicit iteration scope
3. In the builtins namespace
4. Nowhere; assignment expressions are forbidden in filters