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Proper parallel version of Raspberry Pi cluster code from https://www.the-diy-life.com/can-my-water-cooled-raspberry-pi-cluster-beat-my-macbook/
# Requires pip install unsync
import time
from unsync import unsync
import multiprocessing as mp
import sys
#Start and end numbers
start_number = 1
num_processes = mp.cpu_count()
def chunks(seq, chunks):
size = len(seq)
start = 0
for i in range(1, chunks + 1):
stop = i * size // chunks
yield seq[start:stop]
start = stop
@unsync(cpu_bound=True)
def find_in_range(seq):
noPrimes = 0
#Loop through each number, then through the factors to identify prime numbers
primes = []
for candidate_number in seq:
found_prime = True
for div_number in range(2, candidate_number):
if candidate_number % div_number == 0:
found_prime = False
break
if found_prime:
primes.append(candidate_number)
noPrimes += 1
return primes
def run():
#Create variable to store the pr
# ime numbers and a counter
primes = []
ranges = chunks(list(range(2, upper_bound)), num_processes)
# for l in ranges:
# print(list(l))
# print(len(list(ranges)))
#Record the test start time
start = time.time()
tasks = []
for r in ranges:
tasks.append(find_in_range(r))
for t in tasks:
# print(t.result())
primes.extend(t.result())
#Once all numbers have been searched, stop the timer
end = round(time.time() - start, 2)
#Display the results, uncomment the last to list the prime numbers found
print('Find all primes up to: ' + str(upper_bound))
print('Time elasped: ' + str(end) + ' seconds')
print('Number of primes found ' + str(len(primes)))
#print(primes)
if __name__ == "__main__":
upper_bound = int(input("Number of primes: "))
print(f"Using {num_processes} cores.")
run()
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