tail

[Chris Angelico]

On Thu, 12 May 2022 at 06:03, Marco Sulla <Marco.Sulla.Python at gmail.com> wrote:
> I suppose this function is fast. It reads the bytes from the file in chunks
> and stores them in a bytearray, prepending them to it. The final result is
> read from the bytearray and converted to bytes (to be consistent with the
> read method).
>
> I suppose the function is reliable. File is opened in binary mode and only
> b"\n" is searched as line end, as *nix tail (and python readline in binary
> mode) do. And bytes are returned. The caller can use them as is or convert
> them to a string using the encoding it wants, or do whatever its
> imagination can think :)
>
> Finally, it seems to me the function is quite simple.
>
> If all my affirmations are true, the three obstacles written by Chris
> should be passed.

Have you actually checked those three, or do you merely suppose them to be true?

> I'd very much like to see a CPython implementation of that function. It
> could be a method of a file object opened in binary mode, and *only* in
> binary mode.
>
> What do you think about it?

Still not necessary. You can simply have it in your own toolkit. Why
should it be part of the core language? How much benefit would it be
to anyone else? All the same assumptions are still there, so it still
isn't general, and you may as well just *code to your own needs* like
I've been saying all along. This does not need to be in the standard
library. Do what you need, assume what you can safely assume, and
other people can write different code.

I don't understand why this wants to be in the standard library.

ChrisA