Joblib is designed specifically to wrap around multiprocessing for the purposes of simple parallel looping. I suggest using that instead of grappling with multiprocessing directly.
The simple case looks something like this:
from joblib import Parallel, delayed
Parallel(n_jobs=2)(delayed(foo)(i**2) for i in range(10)) # n_jobs = number of processes
The syntax is simple once you understand it. We are using generator syntax in which delayed is used to call function foo with its arguments contained in the parentheses that follow.
In your case, you should either rewrite your for loop with generator syntax, or define another function (i.e. 'worker' function) to perform the operations of a single loop iteration and place that into the generator syntax of a call to Parallel.
In the later case, you would do something like:
Parallel(n_jobs=2)(delayed(foo)(parameters) for x in range(i,j))
where foo is a function you define to handle the body of your for loop. Note that you do not want to append to a list, since Parallel is returning a list anyway.
