Updating variables in Multi-processing

[nilamo]

I think that's because you're trying to access the value within the Manager, after the manager's been cleaned up from the with block. Try this:

if __name__ == '__main__':
    with multiprocessing.Manager() as manager:
        with multiprocessing.Pool(6) as p:
            error_value = manager.Value('i', 0)
            args = itertools.product(input_list, [error_value])
            results = p.map(get_data, args)
 
        for result in results:
              ...
        print("Total errors:", error_value.value)