获取上月的最后一天，格式为yyyy-mm-dd

import datetime
import calendar

# 获取当前日期
current_date = datetime.date.today()

# 计算上个月的年份和月份
last_month = current_date - datetime.timedelta(days=current_date.day)
last_month_year = last_month.year
last_month_month = last_month.month

# 计算上个月的最后一天
last_day_of_last_month = calendar.monthrange(last_month_year, last_month_month)[1]

# 格式化日期
formatted_date = last_month.replace(day=last_day_of_last_month).strftime('%Y-%m-%d')

print(formatted_date)