Returns a uw_sws.models.Term object,
    for the term before the term given.

def get_term_before(aterm):
    """
    Returns a uw_sws.models.Term object,
    for the term before the term given.
    """
    prev_year = aterm.year
    prev_quarter = QUARTER_SEQ[QUARTER_SEQ.index(aterm.quarter) - 1]

    if prev_quarter == "autumn":
        prev_year -= 1

    return get_term_by_year_and_quarter(prev_year, prev_quarter)