from ExternalPythonFile import ExternalFunction

valuelist = []
for a,b in tuplelist:
    value = ExternalFunction(a,b)
    # more functions here
    valuelist.append(value)
print(len(valuelist))

from ExternalPythonFile import ExternalFunction
from joblib import Parallel, delayed, parallel_backend
import multiprocessing

valuelist = []

def TupleFunction(a,b):
        value = ExternalFunction(a,b)
        # more functions here
        valuelist.append(value)

with parallel_backend('multiprocessing'):
    Parallel(n_jobs=10)(delayed(TupleFunction)(a,b) for a,b in tuplelist)

print(len(valuelist))

srun --ntasks=1 --ncpus-per-task=10 python3 MainFileJoblib.py