def _pprint_seq(seq, _nest_lvl=0, max_seq_items=None, **kwds):
    """
    internal. pprinter for iterables. you should probably use pprint_thing()
    rather then calling this directly.

    bounds length of printed sequence, depending on options
    """
    if isinstance(seq, set):
        fmt = "{{{body}}}"
    else:
        fmt = "[{body}]" if hasattr(seq, '__setitem__') else "({body})"

    if max_seq_items is False:
        nitems = len(seq)
    else:
        nitems = max_seq_items or get_option("max_seq_items") or len(seq)

    s = iter(seq)
    # handle sets, no slicing
    r = [pprint_thing(next(s),
                      _nest_lvl + 1, max_seq_items=max_seq_items, **kwds)
         for i in range(min(nitems, len(seq)))]
    body = ", ".join(r)

    if nitems < len(seq):
        body += ", ..."
    elif isinstance(seq, tuple) and len(seq) == 1:
        body += ','

    return fmt.format(body=body)