Promise.all like function for python running in threads

parallel_functions.py

import concurrent.futures
from time import sleep

def expensive_computation(number):
    sleep(10)
    return number

class Runnable:
    def __init__(self, original_target, *args, **kwargs):
        self.original_target = original_target
        self.args = args
        self.kwargs = kwargs
    def run(self):
        self.original_target(*self.args, **self.kwargs)

def run_parallel(*fns: Runnable):
    with concurrent.futures.ThreadPoolExecutor() as executor:
        futures = [
            executor.submit(fn.original_target, *fn.args, **fn.kwargs) for fn in fns
        ]
        return [future.result() for future in futures]

# PARALLEL
a, b, c = run_parallel(
    Runnable(expensive_computation, 1),
    Runnable(expensive_computation, 2),
    Runnable(expensive_computation, 3),
)
print(a)
print(b)
print(c)
print("\n")

# SEQUENTIAL
for number in [1,2,3]:
    print(expensive_computation(number))


# Do keep in mind the python GIL limitation. threading will only be good if your computation 
# happens outside of python (or if it escapes python ASAP, like an http request does)