如何计算每个月的最后一周？

import datetime
import calendar

def calculate_last_week_of_month():
    # 获取当前日期
    today = datetime.date.today()
    
    # 获取当前月份的总天数
    _, last_day = calendar.monthrange(today.year, today.month)
    
    # 计算当前月份的最后一天
    last_day_of_month = datetime.date(today.year, today.month, last_day)
    
    # 判断最后一天是否在最后一周
    if last_day_of_month.weekday() == 6:
        start_date = last_day_of_month - datetime.timedelta(days=6)
        end_date = last_day_of_month
    else:
        start_date = last_day_of_month - datetime.timedelta(days=last_day_of_month.weekday())
        end_date = last_day_of_month + datetime.timedelta(days=6 - last_day_of_month.weekday())
    
    return start_date, end_date

# 调用函数计算最后一周的起始日期和结束日期
start_date, end_date = calculate_last_week_of_month()
print("最后一周的起始日期：", start_date)
print("最后一周的结束日期：", end_date)