datetime
from datetime import datetime, timedelta, date
fmt：指定日期字符串的格式，其中%Y表示四位年份，%m表示两位月份，%d表示两位日
将日期字符串转为日期对象
datetime.striptime(date_str,fmt)
date_str = "2022-01-01"
date_obj = datetime.strptime(date_str, "%Y-%m-%d")
print(date_obj)# 输出：2022-01-01 00:00:00
将日期对象转为字符串
datetime.striptime(fmt)
date_obj = datetime(2022, 1, 1)
date_str = date_obj.strftime("%Y-%m-%d")
print(date_str)# 输出：2022-01-01
timedelta
timedelta是datetime模块中的一个类，用于表示时间间隔（即时间差）。它可以用来进行时间的加减运算，并且可以表示不同单位的时间差，如天、小时、分钟。常用于对天的处理，例如前一天、后一天等。
timedelta(days=0, seconds=0, microseconds=0, milliseconds=0, minutes=0, hours=0, weeks=0)
天的间隔
from datetime import datetime, timedelta, datedelta = timedelta(days=1)
print(delta)# 输出： 1 day, 0:00:00date_obj = datetime(2022, 1, 1)
previous_day = date_obj - timedelta(days=1)
next_day = date_obj + timedelta(days=1)
print(previous_day)
print(next_day)# 输出：
# 2021-12-31 00:00:00
# 2022-01-02 00:00:00relativedelta
relativedelta是dateutil库中的一个类，用于计算两个日期之间的差距，并且可以实现灵活的日期运算。relativedelta相比timedelta更为灵活，可以实现更复杂的日期运算，如计算两个日期之间的年数、月数、星期数等。
dateutil属于第三方库，需要安装后才能使用。
from dateutil.relativedelta import relativedeltarelativedelta(years=0, months=0, days=0, weeks=0, hours=0, minutes=0, seconds=0, microseconds=0)月的间隔
date_obj = datetime(2022, 1, 1)
previous_month = date_obj - relativedelta(months=1)
next_month = date_obj + relativedelta(months=1)
print(previous_month)
print(next_month)# 输出
# 2021-12-01 00:00:00
# 2022-02-01 00:00:00其他功能
博主也总结了自己常用的几个功能，封装成了函数，供大家参考使用
分别是三个功能：拆分年月日时分秒、拆分年月日、获取两个时间间隔的日期列表
from datetime import datetime, timedeltafrom ProjectStart.set_logger import USE_LOGGER# 拆分为年月日 与 时分秒
def handle_date_and_time(start_time, end_time, fmt='%Y-%m-%d %H:%M:%S'):"""将传入的开始和结束时间，转为字符串拆分成【年月日】 与 【时分秒】:param start_time: 开始日期:param end_time: 结束日期:param fmt: 对应的日期格式:return: 返回拆分后的值"""data_dict = {'data': "", "warning_info": "", "error_info": "", }try:# 获取拆分后的时间格式if isinstance(start_time, str) and isinstance(end_time, str):start_date_str = start_time.split(" ")[0]start_time_str = start_time.split(" ")[-1]end_date_str = end_time.split(" ")[0]end_time_str = end_time.split(" ")[-1]elif isinstance(start_time, datetime) and isinstance(end_time, datetime):try:start_date_str = datetime.strftime(start_time, fmt).split(" ")[0]start_time_str = datetime.strftime(start_time, fmt).split(" ")[-1]end_date_str = datetime.strftime(end_time, fmt).split(" ")[0]end_time_str = datetime.strftime(end_time, fmt).split(" ")[-1]except ValueError:data_dict["error_info"] = "日期类型格式转换失败"return data_dictelse:data_dict["error_info"] = "数据类型不一致"return data_dictdata_dict["data"] = start_date_str, start_time_str, end_date_str, end_time_strexcept Exception as e:USE_LOGGER.exception(e)finally:return data_dict# 拆分日 日期
def split_day_time(start_time, end_time, whole_fmt='%Y-%m-%d %H:%M:%S', date_fmt='%Y-%m-%d', split_day=1):"""按照指定拆分的日间隔，拆分为列表:param start_time: 开始日期:param end_time: 结束日期:param whole_fmt: 对应的整个日期格式:param date_fmt: 对应日的日期格式:param split_day: 拆分的间隔:return: 返回嵌套列表，每一个子列表为固定时间间隔的值"""data_dict = {'data': "", "warning_info": "", "error_info": "", }ever_date_list = []handle_result_dict = handle_date_and_time(start_time, end_time, fmt=whole_fmt)if handle_result_dict["error_info"]: returnstart_date_str, start_time_str, end_date_str, end_time_str = handle_result_dict["data"]if start_date_str == start_time_str or end_date_str == end_time_str:start_time_str = ""end_time_str = ""try:ever_date = datetime.strptime(start_date_str, date_fmt).date()end_date = datetime.strptime(end_date_str, date_fmt).date()if ever_date == end_date:ever_date_list.append([f"{ever_date} {start_time_str}" if start_time_str else f"{ever_date}",f"{ever_date} {end_time_str}" if end_time_str else f"{ever_date}"])else:while ever_date < end_date:new_start_date = f"{ever_date} {start_time_str}" if start_time_str else f"{ever_date}"ever_date += timedelta(days=split_day)ever_date = ever_datenew_end_date = f"{ever_date} {end_time_str}" if end_time_str else f"{ever_date}"ever_date_list.append([new_start_date, new_end_date])data_dict["data"] = ever_date_listexcept ValueError:data_dict["error_info"] = "日期类型格式转换失败"return data_dictfinally:return data_dict# 获取每一天时间列表
def get_day_date_list(start_time, end_time, whole_fmt='%Y-%m-%d', date_fmt='%Y-%m-%d', out_fmt='%Y-%m-%d'):data_dict = {'data': "", "warning_info": "", "error_info": "", }day_date_list = []handle_result_dict = handle_date_and_time(start_time, end_time, fmt=whole_fmt)if handle_result_dict["error_info"]: returntry:start_date_str, start_time_str, end_date_str, end_time_str = handle_result_dict["data"]start_date = datetime.strptime(start_date_str, date_fmt).date()end_date = datetime.strptime(end_date_str, date_fmt).date()delta = end_date - start_date# 生成每一天的日期并添加到列表中for i in range(delta.days + 1):date = start_date + timedelta(days=i)day_date_list.append(date.strftime(out_fmt))data_dict["data"] = day_date_listexcept ValueError:data_dict["error_info"] = "日期类型格式转换失败"return data_dictfinally:return data_dictif __name__ == '__main__':# s_time = "2024-01-09 00:00:00"# e_time = "2024-01-12 00:00:00"# w_fmt = '%Y-%m-%d %H:%M:%S'# d_fmt = '%Y-%m-%d's_time = "2024-01-09"e_time = "2024-01-20"w_fmt = '%Y-%m-%d'd_fmt = '%Y-%m-%d'result = split_day_time(s_time, e_time, w_fmt, d_fmt)print(result)
