How to return a value from a shell script in a python script

Question

I have a python script which requires a value from a shell script.

Following is the shell script (a.sh):

#!/bin/bash
return_value(){
  value=$(///some unix command)
  echo "$value"
}

return_value

Following is the python script:

Import subprocess
answer = Subprocess.call([‘./a.sh’])
print("the answer is %s % answer")  

But its not working.The error is "ImportError : No module named subprocess ". I guess my verison (Python 2.3.4) is pretty old. Is there any substitute for subprocess that can be applied in this case??

Answer 1

Use subprocess.check_output:

import subprocess
answer = subprocess.check_output(['./a.sh'])
print("the answer is {}".format(answer))

help on subprocess.check_output:

>>> print subprocess.check_output.__doc__
Run command with arguments and return its output as a byte string.

Demo:

>>> import subprocess
>>> answer = subprocess.check_output(['./a.sh'])
>>> answer
'Hello World!\n'
>>> print("the answer is {}".format(answer))
the answer is Hello World!

a.sh :

#!/bin/bash
STR="Hello World!"
echo $STR