Question

How to achieve the following functionality:

1. Python executes a shell command, which waits for the user to input something
2. after the user typed the input, the program responses with some output
3. Python captures the output

Answer 1

You probably want subprocess.Popen. To communicate with the process, you’d use the communicate method.

e.g.

process=subprocess.Popen(['command','--option','foo'],
                         stdin=subprocess.PIPE,
                         stdout=subprocess.PIPE,
                         stderr=subprocess.PIPE)
inputdata="This is the string I will send to the process"
stdoutdata,stderrdata=process.communicate(input=inputdata)