python取上月、下月、上双月的月份、第一天及最后一天

import datetime, calendar

'''
# python取下个月月份
def month_1():
    now_time = datetime.datetime.now()
    week, days_num = calendar.monthrange(now_time.year, now_time.month)
    print(week, days_num)
    end_day_in_mouth = now_time.replace(day=days_num)
    next_mouth = end_day_in_mouth + datetime.timedelta(days=1)
    return end_day_in_mouth.day, next_mouth.month


# python取上个月月份
def month_2():
    now_time = datetime.datetime.now()
    end_day_in_mouth = now_time.replace(day=1)
    next_mouth = end_day_in_mouth - datetime.timedelta(days=1)
    return next_mouth.month, next_mouth.day


month_last_day = month_1()[0]   # 本月最后一天
next_month = month_1()[1]    # 下月月份
# next_month_last_day = month_1()[2]    # 下月最后一天
last_month = month_2()[0]     # 上月月份
# last_month_last_day = month_2()[1]     # 上月最后一天

print(month_last_day)
print(next_month)
# print(next_month_last_day)
print(last_month)
# print(last_month_last_day)
'''

# 当前时间，月，天，第一天，最后一天
time = datetime.datetime.now()
month = time.month
day = time.day
print('当前月份：', month)
print('当前天:', day)

first_day_month = datetime.date(time.year, time.month, 1)
print('当前月的第一天:' + str(first_day_month))

days_num = calendar.monthrange(first_day_month.year, first_day_month.month)[1]  # 获取当前月有多少天
last_day_month = first_day_month + datetime.timedelta(days=days_num - 1)
print('当前月最后一天:' + str(last_day_month))

# 上月月份、最后一天、第一天
last_month_last_day = first_day_month - datetime.timedelta(days=1)    # timedelta是一个不错的函数
last_month = last_month_last_day.month
print('上月月份', last_month)
print('上月最后一天:' + str(last_month_last_day))
last_month_first_day = datetime.date(last_month_last_day.year, last_month_last_day.month, 1)
print('上月第一天:' + str(last_month_first_day))

# 下月月份、第一天、最后一天
next_month_first_day = first_day_month + datetime.timedelta(days=days_num)
next_month = next_month_first_day.month
print('下月月份', next_month)
print('下个月的第一天:' + str(next_month_first_day))
next_month_days = calendar.monthrange(next_month_first_day.year, next_month_first_day.month)[1]  # 获取下个月有多少天
next_month_last_day = next_month_first_day + datetime.timedelta(days=next_month_days - 1)
print('下个月最后一天:' + str(next_month_last_day))

# 上两月月份、第一天、最后一天
last_2_month_last_day = last_month_first_day - datetime.timedelta(days=1)
last_2_month = last_2_month_last_day.month
print('上两月月份', last_2_month)
last_2_month_first_day = datetime.date(last_2_month_last_day.year, last_2_month_last_day.month, 1)
print('上两月的第一天:' + str(last_2_month_first_day))


# 如果当前日小于14号，则更新上月数据，如果当前月大于等于15号，则更新当月数据
if day < 14:
    date_start = last_2_month_first_day     # 上两月第一天
    date_end = last_day_month        # 本月最后一天
else:
    date_start = last_month_first_day      # 上月第一天
    date_end = next_month_last_day     # 下月最后一天
print(date_start, date_end)