Learning python networking

[Paul Pittlerson]

I'm sorry if this is a bit late of a response, but here goes.

Big thanks to Chris Angelico for his comprehensive reply, and yes, I do have some questions!


> On Thursday, January 9, 2014 1:29:03 AM UTC+2, Chris Angelico wrote:
> Those sorts of frameworks would be helpful if you need to scale to
> infinity, but threads work fine when it's small.
That's what I thought, but I was just asking if it would be like trivially easy to set up this stuff in some of those frameworks. I'm sticking to threads for now because the learning curve of twisted seems too steep to be worth it at the moment.

> Absolutely! The thing to look at is MUDs and chat servers. Ultimately,
> a multiplayer game is really just a chat room with a really fancy
> front end.
If you know of any open source projects or just instructional code of this nature in general I'll be interested to take a look. For example, you mentioned you had some similar projects of your own..?


> The server shouldn't require interaction at all. It should accept any
> number of clients (rather than getting the exact number that you
> enter), and drop them off the list when they're not there. That's a
> bit of extra effort but it's hugely beneficial.
I get what you are saying, but I should mention that I'm just making a 2 player strategy game at this point, which makes sense of the limited number of connections.

> One extremely critical point about your protocol. TCP is a stream -
> you don't have message boundaries. You can't depend on one send()
> becoming one recv() at the other end. It might happen to work when you
> do one thing at a time on localhost, but it won't be reliable on the 
> internet or when there's more traffic. So you'll need to delimit
> messages; I recommend you use one of two classic ways: either prefix
> it with a length (so you know how many more bytes to receive), or
> terminate it with a newline (which depends on there not being a
> newline in the text).
I don't understand. Can you show some examples of how to do this?

> Another rather important point, in two halves. You're writing this for
> Python 2, and you're writing with no Unicode handling. I strongly
> recommend that you switch to Python 3 and support full Unicode.
Good point, however the framework I'm using for graphics does not currently support python3. I could make the server scripts be in python3, but I don't  think the potential confusion is worth it until the whole thing can be in the same version.


> Note, by the way, that it's helpful to distinguish "data" and "text",
> even in pseudo-code. It's impossible to send text across a socket -
> you have to send bytes of data. If you keep this distinction clearly
> in your head, you'll have no problem knowing when to encode and when
> to decode. For what you're doing here, for instance, I would packetize
> the bytes and then decode into text, and on sending, I'd encode text
> (UTF-8 would be hands-down best here) and then packetize. There are
> other options but that's how I'd do it.
I'm not sure what you are talking about here. Would you care to elaborate on this please (it interests and confuses) ?


I'm posting this on google groups, so I hope the formatting turns out ok :P thanks.