Nathaniel Manista <nathaniel@google.com> added the comment: ... and while we're here, how about StackSummary.from_list's "a_list" parameter as well: 3) Can it be Iterable? It looks like it can be Iterable? Is it fine for it to be Iterable? 4) Should the component type of "a_list" be FrameSummary? Is the support for Tuple[str, int, str, Optional[str]] merely backward-looking, or is new code encouraged to pass Tuple[str, int, str, Optional[str]] objects? ---------- title: Confirm the type of traceback.format_list post-3.5 -> Confirm the types of parameters of traceback.format_list and traceback.StackSummary.from_list post-3.5 _______________________________________ Python tracker <report@bugs.python.org> <https://bugs.python.org/issue34648> _______________________________________