https://docs.python.org/3.7/library/socket.html#socket.socket.close says "it is recommended to close() [sockets] explicitly, or to use a with statement around them", but in the example code on the same page at https://docs.python.org/3.7/library/socket.html#example correct use of the .close() method seems to be missing.

Which example?  (It might be easiest to just generate a PR with your suggested improvement.)

As I am learning from the examples, I don't have the confidence to propose a fix to them. :-P

For the IPv4-and-IPv6 "Echo server program": should s be closed at some point after "conn, addr = s.accept()"? Should s be closed on the line immediately after "conn, addr = s.accept()", should it be closed on the last line (after the "with conn:" context is exited), or is either acceptable?

Should the "very simple network sniffer with raw sockets on Windows" have a with statement or "s.close()"? Should the "communicate to a CAN network using the raw socket protocol" example have a with statement or "s.close()"?

Of course it's possible that I'm misunderstanding one or more things.

I think in the echo examples the 'with conn' block should be indented and a
'with s:' added around it.

The network sniffer should probably use a with statement with the
created socket.

The CAN example ends only on ctrl-C, and could go into a fast spin
loop on error, so it probably needs a more extensive rewrite.

Heh, of course the socket server also only ends with ctl-C.  And I misread the CAN example, it won't spin because the read isn't wrapped in a try/except.  So yes, that should use a with on the socket as well, since the with will close the socket on a ctl-C, unlike a close statement after the loop which will never be reached.

Lisa, would you care to wrap this one up?

I submitted a pull request, #4181, to fix this issue. I am now waiting for my contributor agreement to be approved.