I need to run in parallel multiple functions. I tried this
from multiprocessing import Pool
def smap(f, *args):
return f(*args)
def somma(*args):
a=args[0]
b=args[1]
return a+b
def prodotto(*args):
a=args[0]
b=args[1]
return a*b
pool = Pool(processes=2)
a=2
b=4
res=pool.map(smap, [(somma,a,b),(prodotto,a,b)])
print(res)
with the following error:
TypeError: 'tuple' object is not callable
What's wrong?
You are passing the entire tuple as the first argument f to function smap, which is not a function as you intended. You can change smap to:
def smap(f_args):
f, *args = f_args
return f(*args)
This will correctly accept only one argument from Pool.map and split f and args inside the call.
You are expecting the pool.map internals to do the unpacking in smap for you but this is something which the logic cannot handle. You need to explicitely do it yourself.
def smap(params):
function, *args = params
return function(*args)
Just use starmap because map supports only one iterable argument
https://docs.python.org/3/library/multiprocessing.html#multiprocessing.pool.Pool.starmap
