import multiprocessing, os

def f(n, a):
    n.value = 3.1415927
    for i in range(len(a)):
        a[i] = -a[i]
    print('{0}: finished'.format(os.getpid()))

num = multiprocessing.Value('d', 0.0) # 'd' means double
arr = multiprocessing.Array('i', range(10)) # 'i' means signed int

print(num.value)
print(arr[:])

p = multiprocessing.Process(target=f, args=(num, arr))
p.start()
p.join()

print(num.value)
print(arr[:])
print('{0}: finished'.format(os.getpid()))