def sanitize_num_processes(num_processes, min_processes, parallel=False):
    """
    Returns False to prevent parallel processing in case more processes have
    been requested than can be used.
    :param num_processes: How many processes have been requested
    :param min_processes: Minimum number of cores to keep free
    :param parallel: If parallel is requested
    :return bool: True if num_processes is sensible
    """
    if parallel:
        if num_processes < min_processes:
            parallel = False
    return parallel