Solution

Encore merci benja !

Est-ce qu’il est correct de dire qu’en faisant [Pool(N)] * M je fais en fait M références au même objet ?

Quoi qu’il en soit voici la solution en utilisant plusieurs dortoirs. Maintenant les nourrissons peuvent tous commencer leur sieste en même temps et le temps total est égal au temps de la plus longue sieste.

Il fallait faire comme ça pour avoir plusieurs pools:

barracks = []
for i in range(0, int(nurserySize/dormitorySize) + 1):
 barracks.append(Pool(dormitorySize))

Le script en entier (j’ai viré la méthode 1.) :

#!/usr/bin/env python3
"""Make all the toddlers in the nursery have their nap."""
from multiprocessing import Pool
from random import randint, sample
from time import sleep, time
import string
from pprint import pprint
"""What a toddler does when he’s having his nap."""
def nap(toddler):
 time = randint(0,4)
 print(toddler+' Zzz...', end=' ', flush=True)
 sleep(time)
 return(toddler, time)
"""Populate the nursery with toddlers."""
nurserySize = 11
toddlers = []
while (len(toddlers) < nurserySize):
 # Every toddler has a name
 toddlers.append(''.join(sample(string.ascii_lowercase,randint(3,7))).capitalize())
"""For all toddlers, make them nap grouped in available dormitories.
The nap is finished for all the toddlers in a dormitory when the last one wakes up."""
dormitorySize = 4
"""Nap all the toddlers at once."""
start = time()
barracks = []
for i in range(0, int(nurserySize/dormitorySize) + 1):
 barracks.append(Pool(dormitorySize))
sleepAmount = 0
dormitories = []
j = 0
# The callback function will be called when the pool has finished.
def fillDormitory(toddlers):
 dormitories.append(toddlers)
print(str(len(toddlers))+' toddlers going to sleep '+str(dormitorySize)+' by '+str(dormitorySize)+' in '+str(len(barracks))+' dormitories.')
for i in range(0, nurserySize, dormitorySize):
 barracks[j].map_async(nap, toddlers[i:i+dormitorySize], callback=fillDormitory)
 j += 1
for b in barracks:
 b.close()
 b.join()
# Count total sleep amount.
for dormitory in dormitories:
 for toddler in dormitory:
 sleepAmount += toddler[1]
print(dormitories)
_time = time() - start
_ratio = sleepAmount/_time
print("\n",' → Tooks '+str(_time)+' seconds for '+str(sleepAmount)+' of sleep. ('+str(_ratio)+')',"\n")

EDIT: J’ai le sentiment que je devrais pouvoir me passer d’utiliser un indice explicite (j), ça ne doit pas être très pythonesque comme manière de faire :/