Get the last weeks.

def get_last_weeks(number_of_weeks):
    """Get the last weeks."""
    time_now = datetime.now()
    year = time_now.isocalendar()[0]
    week = time_now.isocalendar()[1]
    weeks = []
    for i in range(0, number_of_weeks):
        start = get_week_dates(year, week - i, as_timestamp=True)[0]
        n_year, n_week = get_year_week(start)
        weeks.append((n_year, n_week))

    return weeks