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python-2.7shellpopen

Pass integer input argument for Popen.communicate()

I am pretty new to python and I am stuck with something now. I am using python 2.7. I am trying to automate a command in shell for which I wrote a python script. I have to input an integer value to the shell for which I am using Popen.communicate(input='2'). Though input is passed, it is passed as a string and the subprocess needs it as a numeric value. When I try to pass it as a numberic value like Popen.communicate(input=2) it throws the following error :

TypeError: 'int' object has no attribute '__getitem__'

So is there any way to send the input as a numeric value ??

Here is the code I use : 

import sys
from subprocess import Popen, PIPE, STDOUT

cmd = ["sudo", "./sbt", "project java-examples", "run"]
proc = Popen(cmd, bufsize=4096, shell=False, stdout=PIPE, stdin=PIPE, stderr=STDOUT)

string = proc.communicate(input='2')
print string[0]
proc.stdin.close()

Edit : Sorry that I didn't mentioned this at the first place. My java application has multiple main classes hence the compiler ask which class to be executed, and I need to enter the same number every time,which is why I am trying to automate it. When I am passing a string value it throws numberformatexception.

Solution

  • Finally I found the solution for this. Well the solution to this was pretty simple

    when I changed

    string = proc.communicate(input='2')

    to

    string = proc.communicate(input='2\n')

    it worked fine.