Get list of tuples of stacked for loop values

Question

While trying to speed up:

l = some_value
for i in range(1000):
    for j in range(1000):
        for k in range(1000):
            function(i, j, k, l)

I stumbled upon multiprocessing.Pool().starmap() however it requires the iterated values to be passed in as an interator [(0, 0, 0), (1, 0, 0), ...] . Is there a fast way to get this list of tuples containing the for loop values?

Answer 1

Here's an iterator you need:

iterator = ((i, j, k, l) for i in range(1000) 
                         for j in range(1000) 
                         for k in range(1000))