Python 3 Programming Tutorial - Sockets Binding and listening

Key Takeaways

hello everybody and welcome to another Python 3 tutorial video with sockets so in the first video I showed you guys uh just the creation of a socket and using it to uh request some data uh then we did a port scanner then we combined threading and socket for a threaded socket or a threaded Port scanner rather um now we're going to go back to the purpose of sockets again again and we're going to be talking about sending and receiving data using sockets uh so with that let's go ahead and get started so I think um I'm just going to do one big control a and delete here um and then we'll go ahead and here we're going to import socket and then we're also going to import CIS for system now uh we're going to do a couple of things first we're going to say host and host is just going to be blank for now um it's sort of like arbitrary uh basically this just means that you're willing to accept um or it's going to be like all interfaces pretty much then Port we can specify any port that we want uh for this let's just do 5555 um you could put almost anything in there that you want but we'll be using 5555 so now what we want to do is we're going to say s equals socket. socket this should be pretty darn familiar by now socket. aore I oops unit in and then socket uh do sockor stream like that um again just the address family and sock stream uh so we can use the internet not UDP next um at this point we've created a socket now what we're ready to do is we want to bind this socket so let's say try s. bind and this has to be again uh two so we're going to say host and Port so we bind that and then um accept um and really the only exception we want to accept here is a socket error um accept socket error as e and then if we get that we're going to print string e so what was that error let's just print it out now at this point we've bound the socket and now what we can do is we can go s. listen and then in here you put a parameter we're going to put five and basically what this parameter does is it's it's kind of like a q or it is a Q and it's basically how many incoming connections will we fit into Q before we turn the connection away because we have too many um so that's what we're going to be doing so we're going to be listening um on Port uh 5,555 and now we will be able to make a connection um to it so uh let's do the following so we're going to go uh connection address equals s do accept and then we can actually go ahead and like we can print out some information on the connection so we can go like this we could say print connected to colon and we'll do plus uh addr for address zero and then we'll do another plus this will be okay there and then plus addr one and actually let's do string one and that should do it for us so now uh we should be able to run this first let's see if we get any error running it does not look like we did so we're running and we're waiting for a connection now what you can do is come over to your command. exe or if you're in bash and use the following commands so you could say tnet um and then Local Host 5555 hit enter and there might be a couple of can't speak couple of trouble for some of you guys um but first of all this worked we've it we've got the hey we made this connection first of all the connection is over at this point there was not really retaining any connection um but anyway you can see that we were able to make that connection it was listening and it connected and received some information from the person who connected to it now um if you're on Windows and you type tnet and it says tnet does not exist or that command is you know doesn't exist you go to uh you know Start Control Panel bring that down here you're going to want to go to programs and then over programs and features turn Windows features on or off click on that and then wait while this makes a list and come on down to tnet client you'll want to make sure that box tell not C tnet client is checked and then tnet will work on your machine similarly if you're on another machine um you know like if you're on Linux or something you might not have tet automatically installed so suseo app to get install telnet and then you'll be able to use telnet Okay so should cover it uh if you guys have any questions or comments uh getting this to work uh feel free to leave them below you it should be able to it should work for you as soon as you uh install tet um so anyways uh that's it as always thanks for watching thanks for all the support subscriptions and until the next video uh where we keep that connection open we do a little bit better uh listening and we do some cool stuff so stay tuned for that