Multiprocessing, Pool.map()
The problem is that log_in is a function that takes two arguments, but your code passes just a single argument to that function: a list with two elements. Try Pool.starmap instead of Pool.map:
p.starmap(log_in, list)From the documentation of Pool.starmap():
Like
map()except that the elements of the iterable are expected to be iterables that are unpacked as arguments.Hence an iterable of
[(1,2), (3, 4)]results in[func(1,2), func(3,4)].