Invoke Python modules from Java

Question

I have a Python interface of a graph library written in C - igraph (the name of library). My need is to invoke the python modules pertaining to this graph library from Java

Answer 1

You can use jep.getValue() to retrieve a value from script's global dictionary.

There are caveats to that concerning scope levels in Python, so most people find it clearer to pass a Java class to python and set the return value in that instance in Python. After the script completes, the Java code will then have the result.

For example:

==> Java

class ReturnValueClass {
   public int scriptResult;
};
ReturnValueClass value = new ReturnValueClass();
jep.set("retval", value);

==> Python

# do something
pass
# write the return value
retval.scriptResult = some_python_value

==> Java

System.out.println(value.scriptResult);

Hope that helps,

Mike (I wrote Jep)