def unique(seq):
seen = set()<EOL>seen_add = seen.add<EOL>"""<STR_LIT>"""<EOL>return [x for x in seq if x not in seen and not seen_add(x)]<EOL>
Remove duplicates from a list in Python while preserving order.

    :param seq: a python list object.
    :return: a list without duplicates while preserving order.