I have a Python program which will run a script in the Wolfram language and then return to the main program. Is it possible to return values/variables to the main program?

This is the code in Python running the Wolfram language code:

os.system('wolfram  -script file.wl')

Then in file.wl, for example, I can run a command such as 1+1, which will give me an output of 2.

Can I then use this value 2 in the rest of my Python program?

e.g. print (ans)
  • $\begingroup$ you might be better off asking in a python forum, seems like to need something equivalent to ToExpression $\endgroup$
    – s0rce
    Dec 29, 2013 at 1:10
  • $\begingroup$ Thanks for help, yes I just want the output from wolfram language accessible to python $\endgroup$
    – Hamoudy
    Dec 29, 2013 at 1:12
  • $\begingroup$ does using Print on the output help? Also, please don't use random tags... this question is not related in anyway to wolfram-alpha-queries or mathematica-education $\endgroup$
    – rm -rf
    Dec 29, 2013 at 1:20
  • $\begingroup$ This is on the raspberry pi and the wolfram command runs wolfram-language. The print outputs to the command window, but after the script runs, I want the variables accessible in python. $\endgroup$
    – Hamoudy
    Dec 29, 2013 at 1:22
  • $\begingroup$ yes, but the tag you used is for Wolfram | Alpha (specifically, querying W|A from Mathematica) :) $\endgroup$
    – rm -rf
    Dec 29, 2013 at 1:27

1 Answer 1


The os.system command will not help you, because it does not return/provide the output of the command executed. What you want is to have a look at this answer on Stack Overflow to see how you can get the stdout of a command into a Python variable.

In your Mathematica script you simply Print the result and with the given method in the other answer you will fetch this result to your Python script.

Here a working example. I don't have a Raspberry Pi and therefore, the command is still good old MathematicaScript for me.

  1. Create a Mathematica script file which I called test.m here with the following content.

  2. Create a runScript.py with the following content. Here I'm using the Python 2.7 function subprocess.check_output:

    import subprocess
    output = subprocess.check_output(['MathematicaScript', '-script', 'test.m'])
    print output
  3. Run the script with something like /usr/bin/python runScript.py.

  • $\begingroup$ Thank you for your response, but I wasn't sure how to implement it. output = Popen(["os.system", "wolfram -script gps.wl"], stdout=PIPE).communicate()[0] But then I get this error: NameError: name 'Popen' is not defined $\endgroup$
    – Hamoudy
    Dec 29, 2013 at 1:52
  • $\begingroup$ @Hamoudy You need to full specify the namespace: subprocess.Popen and subprocess.PIPE etc. Look at the last code-block in this example! $\endgroup$
    – halirutan
    Dec 29, 2013 at 1:55
  • $\begingroup$ I tried, but I get no output: prntscr.com/2erghu $\endgroup$
    – Hamoudy
    Dec 29, 2013 at 2:05
  • $\begingroup$ Yes you need the print otherwise nothing will be outputted $\endgroup$
    – Hamoudy
    Dec 29, 2013 at 2:25
  • $\begingroup$ I tried it, but it shows nothing in the screen. Why? $\endgroup$
    – user11701
    Jan 13, 2014 at 6:46

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