title: Communication between two separate Python engines
body: <p>The problem statement is as follows:</p>
  
  <p>I am working with Abaqus, a program for analyzing mechanical problems. It is basically a standalone Python interpreter with its own objects etc. Within this program, I run a python script to set up my analysis (so this script can be modified). It also contains a method which has to be executed when an external signal is received. These signals come from the main script that I am running in my own Python engine.</p>
  
  <p>For now, I have the following workflow:
  The main script sets a boolean to True when the Abaqus script has to execute a specific function, and pickles this boolean into a file. The Abaqus script regularly checks this file to see whether the boolean has been set to true. If so, it does an analysis and pickles the output, so that the main script can read this output and act on it.</p>
  
  <p>I am looking for a more efficient way to signal the other process to start the analysis, since there is a lot of unnecessary checking going on right know. Data exchange via pickle is not an issue for me, but a more efficient solution is certainly welcome.</p>
  
  <p>Search results always give me solutions with subprocess or the like, which is for two processes started within the same interpreter. I have also looked at ZeroMQ since this is supposed to achieve things like this, but I think this is overkill and would like a solution in python. Both interpreters are running python 2.7 (although different versions)</p>