Python 3 Programming Tutorial - Subprocess module 

SICK

you are the man.

Absolute legend thank you!

So, I played with this and determined that test_subprocess was not getting any arguments passed through. A quick Google search reveals this SO post: stackoverflow.com/questions/10490529/python-subprocess-popen-not-sending-all-arguments-to-shell Which reveals the culprit as shell=True (which is a potential security vulnerability if you have external content (user input, other programs) affecting your built command/arguments anyways). The solution is to call python to run the script instead of using the shell: And the solution to know where the executable is (without hardcoding it) is to use sys.executable, of course you'll quickly realize that you also need an absolute path to the python script so use os.path.abspath (or shutils.abspath): # Main Program from sys import executable from subprocess import call from os.path import abspath x = call((executable, abspath('test_subprocess.py'), '5')) print(x) # now you probably noticed that I'm using a tuple here, but you could concatenate everything into one string # I just find the tuple a little more intuitive. # you'll also notice that I made VAR into the string '5'. All arguments must be strings # for me sys.quit(errorCode) didn't exist so I used sys.exit(errorCode) # I found that non-numeric errorCodes are ignored and 1 is used instead # so you must convert the string argv[1] to an int before returning it in test_subprocess. # test_subprocess from sys import argv, exit def main(arg): exit(arg) if len(argv)>1: try: x = int(argv[1]) except ValueError as e: print(e) exit(666) # use some sentinel that won't be assumed as a valid result main(x) # only get here if argv[1] exists and can be converted to an int # OK so, that's a bit limiting to ONLY be able to pass integer return codes... # so a more advanced method is using Popen and communicate (maybe there's a 3rd party module to simplify this?) # Main Program passes argv[1] to test_subprocess.py and prints it's return value from sys import executable, argv import subprocess from os.path import abspath if len(argv) < 2: sys.exit(1) # error x = subprocess.Popen((executable, abspath('test_subprocess.py')), stdin=subprocess.PIPE, stdout=subprocess.PIPE) # str does not implement buffer, bytes does. so convert strs to bytes with utf-8 encoding data = bytes(argv[1], 'utf-8') result = x.communicate(data) # result[0] is stdout, result[1] is stderr but that isn't PIPEd so it's always None # of course, output is returned as bytes as well bytes_result = result[0] # since I know I'm getting back a string we decode it as utf-8 real_result = bytes_result.decode('utf-8') print('x:', real_result) # x.terminate() # this didn't seem to work so well when I had while True: in the test_subprocess.py (more testing required) # test_subprocess.py import sys # input() or sys.stdin.read() reads strings. # but we had to print BYTES. so use sys.stdin.buffer.read() # to read BYTES in. Since we know those bytes are utf-8 encoded strings # decode them as utf-8 x = sys.stdin.buffer.read().decode('utf-8') try: x = int(x) if x < 100: print('This is some output') # result stdout else: print('Invalid input!') # result stdout, could have been stderr. except Exception: if x == 'hi': print("'ello mate!") # result stdout else: print('someone screwed up!') # result stdout, should probably be stderr... # huh.... maybe now would be a good time to actually, well, WATCH the subprocess module video I came here to watch.... lol # well, that check_output function is kindof nice... LOL. how did I miss that when reading through the docs...

In python 3.6 you could do it like this. channel = input("please put the correct channel") address = input("please put address") subprocess.call(f'bla bla {channel} ect {address}') I haven't tested this code so it may not work, but good luck anyways.

Cyril Attié Not sure, I don't see many people mixing and matching myself. I just happen to think it's super cool. You could learn another language, even as simple as bash, or command line scripting, and mesh with that.

You're right, it's very cool. I just installed Ubuntu in order to familiarize with it before building my own supercomputer, would you have any recommended source to learn bash?

Teu inglês não é ruim, tem alguns erros, mas da pra entender perfeitamente o que você quer dizer. Por curiosidade, esta criando o bot apenas por diversão ou tem algum projeto maior que pretende seguir após fazê-lo ?

O bot é apenas por hobbie. Por enquanto não tenho nenhum outro projeto , provavelmente no futuro , poderei pensar em algo mais para fazer

did he make a tutorial on pipes ??

Omg check it dude.

I don't understand pipes and i want a tutorial on it so much.... It's a good idea but I want sub in the video because my English is not perfect.... Thank you a lot

Does that directory actually exist in your folder structure? You can't cd into a non existent folder. -_-

Create a directory called ensmo or cd to a diferent directory. P.S. It's better to learn the really basic things first.

Really dude? Like I don't want to be too harsh here mate, but you have to learn the basics of a computer and especially the command cd before you can learn programming. Also it says the path can't be found which should obviously mean that there is no directory by the name of 'ensmo'.

check_call allows you to store the output from subprocess to a variable. It's usefull if you want to manipulate the output or get certain bits of data from the output.

pythonprogramming.net

thnx man :)

you need to import subprocess

Thanks.Figured it out.

+eldine kyd With your grammar, your not learning anything but kindergarten.

+alex cohen if that works, it'd probably be simpler to say subprocess.call('python systut.py "check this out" ', shell=true). I think the problem is that python recognizes both ' and " as indicating a string, while windows only recognizes " EDIT: Just saw that that's actually what he did. I still maintain that it's the best way, over the escaped "s.

its deprecated

Pascal Ehrlich which one Os or subprocess

I was gonna say drunk lol

Try watching at 2x speed, he will look normal. (Y)

who cares? you gossip girl

Risofly Does Minecraft If you're in an interactive interpreter, sure. Otherwise, no.

I mean for an interactive interpreter

Love the tuts sentdex, but I was wondering how I could use the subprocess.call with an input so if I had this. channel = input("please put the correct channel") address = input("please put address") subprocess.call(" bla bla {channel} ect {address}") how would I include the channel and address in that specific location, but obviously without the bla bla as I just needed to put something in as a reference.