In the document of "struct" (https://docs.python.org/3.9/library/struct.html#struct.unpack_from), there's typo in it.

The document read
`struct.unpack_from(format, /, buffer, offset=0)`
and I believe it should be
`struct.unpack_from(format, buffer, offset=0)`.

Documents before Python 3.9 has no this typo.

The `/` denotes that `format` is a positional-only argument; you cannot make a call like `struct.unpack_from(format=my_format, buffer=my_buffer)`, it must be `struct.unpack_from(my_format, buffer=my_buffer)` or `struct.unpack_from(my_format, my_buffer)`.  The same syntax can be used to define your own function with positional-only arguments, see https://docs.python.org/3/tutorial/controlflow.html#positional-only-parameters or https://docs.python.org/3/reference/compound_stmts.html#function-definitions

Hi,

I didn't know that and feel sorry to bother you with the non-bug "issue."

Thank you for the quick and thoughtful reply. :-)

Hiankun

On Thu, Dec 2, 2021 at 12:23 PM Zachary Ware <report@bugs.python.org> wrote:

>
> Zachary Ware <zachary.ware@gmail.com> added the comment:
>
> The `/` denotes that `format` is a positional-only argument; you cannot
> make a call like `struct.unpack_from(format=my_format, buffer=my_buffer)`,
> it must be `struct.unpack_from(my_format, buffer=my_buffer)` or
> `struct.unpack_from(my_format, my_buffer)`.  The same syntax can be used to
> define your own function with positional-only arguments, see
> https://docs.python.org/3/tutorial/controlflow.html#positional-only-parameters
> or
> https://docs.python.org/3/reference/compound_stmts.html#function-definitions
>
> ----------
> nosy: +zach.ware
> resolution:  -> not a bug
> stage:  -> resolved
> status: open -> closed
>
> _______________________________________
> Python tracker <report@bugs.python.org>
> <https://bugs.python.org/issue45958>
> _______________________________________
>