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In Python Subprocess Module, we can take the output from an executed command and make it as input for another command, using the input parameter. If you start notepad.exe as a windowed app then python will not get the output. Input Parameter in Python Subprocess Run Function. () () print "Waiting for process to exit." returnCode = process.wait() if returnCode != 0: raise subprocess.CalledProcessError(returnCode, command) sleep(0.05) print "Waiting for async readers to finish." stdoutReader.join() stderrReader.join() # Close subprocess' file descriptors. # Sleep for a short time to avoid excessive CPU use while waiting for data. import subprocess task subprocess.Popen('cat file.txt', shellTrue, stdoutsubprocess. Now, I want to use subprocess to read the output of cat tabdelimited1.txt. In the command line, cat tabdelimited1.txt will output all of the lines. while not stderrQueue.empty(): line = stderrQueue.get() print 'Received stderr: ' + repr(line) # Do stuff with stderr line. However, let's say we wanted to use subprocess. # Process all available lines from the stderr Queue. while not stdoutQueue.empty(): line = stdoutQueue.get() print 'Received stdout: ' + repr(line) # Do stuff with stdout line. while not stdoutReader.eof() or not stderrReader.eof(): # Process all available lines from the stdout Queue. Если кто-то хочет читать как stdout и stderr в то же время, используя потоки, это то, что я придумал: import threading import subprocess import Queue class AsyncLineReader(threading.Thread): def _init_(self, fd, outputQueue): threading.Thread._init_(self) assert isinstance(outputQueue, Queue.Queue) assert callable(fd.readline) self.fd = fd self.outputQueue = outputQueue def run(self): map(, iter(self.fd.readline, '')) def eof(self): return not self.is_alive() and () def getForFd(cls, fd, start=True): queue = Queue.Queue() reader = cls(fd, queue) if start: reader.start() return reader, queue process = subprocess.Popen(command, shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE) (stdoutReader, stdoutQueue) = AsyncLineReader.getForFd(process.stdout) (stderrReader, stderrQueue) = AsyncLineReader.getForFd(process.stderr) # Keep checking queues until there is no more output.