def find_next_in_list(lst, what, start=0, reverse=False):
    """
    Finds the next occurrence of what in lst starting at start.
    :param lst: The list to search
    :param what: The item to find, should be an iterable
    :param start: The starting position in the list
    :param reverse: Set this to True in order to traverse the list towards 0
    :return: False if no occurrence found, index otherwise
    """
    if start < 0 or start >= len(lst):
        return False

    end = -1 if reverse else len(lst)
    step = -1 if reverse else 1

    for i in range(start, end, step):
        if lst[i] in what:
            return i
    return False