In case your process produces significant amounts of output that you don’t want to buffer in memory, you should redirect the output to the electronic trash can: subprocess.run([“pdflatex”, filename], stdout=subprocess.DEVNULL) The special value DEVNULL indicates that the output is sent to the appropriate null device of your operating system (/dev/null on most OSes, nul on … Read more
Check out the subprocess manual. You have options with subprocess to be able to redirect the stdin, stdout, and stderr of the process you’re calling to your own. from subprocess import Popen, PIPE, STDOUT p = Popen([‘grep’, ‘f’], stdout=PIPE, stdin=PIPE, stderr=STDOUT) grep_stdout = p.communicate(input=”one\ntwo\nthree\nfour\nfive\nsix\n”)[0] print grep_stdout You can also interact with a process line by … Read more
You’re doing blocking reads to two files; the first needs to complete before the second starts. If the application writes a lot to stderr, and nothing to stdout, then your process will sit waiting for data on stdout that isn’t coming, while the program you’re running sits there waiting for the stuff it wrote to … Read more
The subprocess.run() function only exists in Python 3.5 and newer. It is easy enough to backport however: def run(*popenargs, **kwargs): input = kwargs.pop(“input”, None) check = kwargs.pop(“handle”, False) if input is not None: if ‘stdin’ in kwargs: raise ValueError(‘stdin and input arguments may not both be used.’) kwargs[‘stdin’] = subprocess.PIPE process = subprocess.Popen(*popenargs, **kwargs) try: … Read more
To open in a different console, do (tested on Win7 / Python 3): from subprocess import Popen, CREATE_NEW_CONSOLE Popen(‘cmd’, creationflags=CREATE_NEW_CONSOLE) input(‘Enter to exit from Python script…’) Related How can I spawn new shells to run python scripts from a base python script?
You obviously can use subprocess.communicate but I think you are looking for real time input and output. readline was blocked because the process is probably waiting on your input. You can read character by character to overcome this like the following: import subprocess import sys process = subprocess.Popen( cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE ) while True: out … Read more
This is now possible as of FFmpeg 2.2 with the -hide_banner option. See also the relevant commit and ticket.
p = subprocess.Popen([sys.executable, ‘/path/to/script.py’], stdout=subprocess.PIPE, stderr=subprocess.STDOUT) That will start the subprocess in background. Your script will keep running normally. Read the documentation here.
Use the subprocess module: import subprocess subprocess.Popen([“fswebcam”, “image.jpg”])
From the documentation at http://docs.python.org/library/subprocess.html: Popen.pid The process ID of the child process. Note that if you set the shell argument to True, this is the process ID of the spawned shell. If shell is false, it should behave as you expect, I think. If you were relying on shell being True for resolving executable … Read more