On Jan 9, 2018 04:12, "Random832" <random832@fastmail.com> wrote:

On Tue, Jan 9, 2018, at 05:46, Nick Coghlan wrote:
> If you view them as comparable to subprocess pipes, then it can be
> surprising that they're not iterable when using a line-oriented
> protocol.
>
> If you instead view them as comparable to socket connections, then the
> lack of iteration support seems equally reasonable.

Sockets are files - there's no fundamental reason a stream socket using a line-oriented protocol (which is a common enough case), or a datagram socket, shouldn't be iterable. Why aren't they?

Supporting line iteration on sockets would require adding a whole buffering layer, which would be a huge change in semantics. Also, due to the way the BSD socket API works, stream and datagram sockets are the same Python type, so which one would socket.__next__ assume? (Plus datagrams are a bit messy anyway; you need to know the protocol's max size before you can call recv.)

I know this was maybe a rhetorical question, but this particular case does have an answer beyond "we never did it that way before" :-).

-n