Python : How to create n processes and iterate over a list

Question

I have a list of numbers as described below (Elements):

Elements = [['1','5'], ['2','5'], ['3','5'], ['4','5'], ['5', '5'], ['6', '5'], ['7', '5'], ['8', '5'], ['9', '5'], ['10', '5']]

I want to call a function main(x1,y1) using process where x1=records[0] , y1=records[1] for records in Elements . I would like to call main() with say 10 processes to work simultaneously on first 10 records from Elements . Once it is finished, call next 10 records from Elements and do the same and repeat until all the records are processed by main(). I am new to python so it would be great if anyone could help me with this.

Here's my code-

def main(x1,y1):
  do something
  do something

import multiprocessing as mp
output = mp.Queue()

processes = [mp.Process(target=main, args=(records[0], records[1], output)) for records in Elements]

# Run processes
for p in processes:
    p.start()

# Exit the completed processes
for p in processes:
    p.join()

# Get process results from the output queue
results = [output.get() for p in processes]

print(results)

Answer 1

You can do something like this with Pool :

from multiprocessing import Pool

PROCESS_COUNT = 10

elements = [['1','5'], ['2','5'], ['3','5'], ['4','5'], ['5', '5'], ['6', '5'], ['7', '5'], ['8', '5'], ['9', '5'], ['10', '5']]

def main(element):
    # let's say you want to have concatenations as the results
    return element[0] + element[1]

pool = Pool(PROCESS_COUNT)
results = pool.map(main, elements)
pool.close()
pool.join()
# now results is a list of concatenations: ['15', '25', '35', '45', '55', '65', '75', '85', '95', '105']