def nprocesses_nthreads(n=CPU_COUNT):
"""
The default breakdown of processes and threads for a given number of cores
Parameters
----------
n: int
Number of available cores
Examples
--------
>>> nprocesses_nthreads(4)
(4, 1)
>>> nprocesses_nthreads(32)
(8, 4)
Returns
-------
nprocesses, nthreads
"""
if n <= 4:
processes = n
else:
processes = min(f for f in factors(n) if f >= math.sqrt(n))
threads = n // processes
return (processes, threads)
def test_factors():
assert factors(0) == set()
assert factors(1) == {1}
assert factors(2) == {1, 2}
assert factors(12) == {1, 2, 3, 4, 6, 12}
assert factors(15) == {1, 3, 5, 15}
