def ensure_required(rlist, required):
    """ Check which keys aren't present. """
    not_present = []
    for k in required:
        if k not in rlist:
            not_present.append(k)
    if len(not_present) != 0:
        print(' Skipping: following required fields not present:')
        for k in not_present:
            print('  %s' % k)
        return False
    return True
