73 - 自带库 - datetime - 时间

datetime 库

Python 的 time 库用于处理时间相关的功能。它提供了获取当前时间、测量时间间隔、延迟执行代码以及转换时间格式等方法。time 库允许程序以秒或更精确的单位进行时间测量，支持不同操作系统的时间函数。它在日志记录、性能测试、动画制作、延迟任务调度等需要时间控制的场景中非常有用。

https://blog.csdn.net/gty931008/article/details/80254806

引入

import datetime

datetime.date 类 日期

time.struct_time(tm_year=2022, tm_mon=4, tm_mday=23, tm_hour=0, tm_min=0, tm_sec=0, tm_wday=5, tm_yday=113, tm_isdst=-1)

datetime.time 类 时间

datetime.datetime 类 日期 + 时间

datetime.timedelta 类 时间差(日、周、小时、分钟、秒)

def __new__(cls, days=0, seconds=0, microseconds=0,milliseconds=0, minutes=0, hours=0, weeks=0):

获得小时数、秒数

from datetime import datetime, timedelta
## 假设有两个时间点
time1 = datetime(2023, 3, 15, 8)  # 2023年3月15日 8时
time2 = datetime(2023, 3, 16, 10) # 2023年3月16日 10时
## 计算两个时间点之间的timedelta
delta = time2 - time1
print(delta)
## 获取delta的小时数
hours = delta.total_seconds() / 3600  # 26.0
second = delta.total_seconds()  # 93600.0 秒
print(f"两个时间之间的差异为：{hours} 小时")
print(f"两个时间之间的差异为：{second} 秒")

relativedelta()时间差（年月日周小时、分钟、秒）

def __init__(self, dt1=None, dt2=None,
years=0, months=0, days=0, leapdays=0, weeks=0,hours=0, minutes=0, seconds=0, microseconds=0,year=None, month=None, day=None, weekday=None,yearday=None, nlyearday=None,hour=None, minute=None, second=None, microsecond=None):
## 使用
from dateutil.relativedelta import relativedelta
now = datetime.datetime.now()  # 现在是2023年11月
latest_time = now+relativedelta(months=-15)  # 减15个月，跨年了
print(latest_time)
## datetime.datetime(2022, 8, 21, 9, 28, 17, 458687)

replace()直接替换修改日期

def replace(self, year=None, month=None, day=None, hour=None,minute=None, second=None, microsecond=None, tzinfo=True,*, fold=None):
now = datetime.datetime.now()  # 现在是2023年11月
latest_time = now.replace(month=10,day=1)
## datetime.datetime(2023, 10, 1, 11, 7, 56, 806271)

对比时间大小

import datetime
timenow = datetime.timedelta(hours=8, minutes=29)
timenow = datetime.timedelta(hours=8, minutes=31)
time830 = datetime.timedelta(hours=8, minutes=30)
if timenow < time830 :
    print("0:00-8:30")  # 29
else:
    print("8:30-23:59")  # 31

n天前的列表

def get_nday_list(n):
    before_n_days = []
    for i in range(0, n)[::-1]:
        day = str(datetime.date.today() - datetime.timedelta(days=i))
        day2 = day.replace("-","")
        before_n_days.append(day2)
    return before_n_days

一天一天的列表

import datetime
def daybyday(t1, t2):
    tt1 = datetime.datetime.strptime(t1, "%Y-%m-%d %H:%M:%S")
    tt2 = datetime.datetime.strptime(t2, "%Y-%m-%d %H:%M:%S")
    cha = tt2 - tt1
    chadays = cha.days
    if chadays == 0:
        # 第一种情况，例如chadays等于0days，在一天内
        if tt1.day == tt2.day:
            print("在一天内")
            return [[t1,t2]]
        # 第二种情况，例如chadays等于0days，在两天内
        if tt1.day != tt2.day:
            print("在两天内")
            month = addzero(str(tt1.month))
            day = addzero(str(tt1.day))
            t1_last = str(tt1.year) + "-" + month + "-" + day + " 23:59:59"
            month = addzero(str(tt2.month))
            day = addzero(str(tt2.day))
            t2_start = str(tt2.year) + "-" + month + "-" + day + " 00:00:00"
            return [[t1, t1_last], [t2_start, t2]]
    if chadays > 0:
        print("在多天内")
        # 第三种情况，例如chadays大于0days
        datelist = []
        # 第一天
        first_day = []
        month = addzero(str(tt1.month))
        day = addzero(str(tt1.day))
        first_day.append(t1)
        first_day.append(str(tt1.year) + "-" + month + "-" + day + " 23:59:59")
        datelist.append(first_day)
        # 中间天
        for i in range(cha.days):
            datel = []
            if i == 0:
                continue
            tt1_add = tt1 + datetime.timedelta(i)
            month = addzero(str(tt1_add.month))
            day = addzero(str(tt1_add.day))
            datel.append(str(tt1_add.year) + "-" + month + "-" + day + " 00:00:00")
            datel.append(str(tt1_add.year) + "-" + month + "-" + day + " 23:59:59")
            datelist.append(datel)
        # 最后一天
        last_day = []
        month = addzero(str(tt2.month))
        day = addzero(str(tt2.day))
        last_day.append(str(tt2.year) + "-" + month + "-" + day + " 00:00:00")
        last_day.append(t2)
        datelist.append(last_day)
        return datelist
def addzero(data):
    if len(data) == 1:
        data = "0"+data
    return data
def run():
    # t1 = "2022-07-01 03:00:00"
    # t2 = "2022-07-01 04:00:00"
    # t1 = "2022-07-01 23:00:00"
    # t2 = "2022-07-02 01:00:00"
    t1 = "2022-06-25 03:00:00"
    t2 = "2022-07-09 15:00:00"
    datelist = daybyday(t1, t2)
    print(datelist)
if __name__ == "__main__":
    run()
    # [["2022-07-01 03:00:00", "2022-07-01 04:00:00"]]
    # [["2022-07-01 23:00:00", "2022-07-01 23:59:59"], 
    # ["2022-07-02 00:00:00", "2022-07-02 01:00:00"]]
    # [["2022-06-25 03:00:00", "2022-06-25 23:59:59"], 
    # ["2022-06-26 00:00:00", "2022-06-26 23:59:59"], 
    # ["2022-06-27 00:00:00", "2022-06-27 23:59:59"], 
    # ["2022-06-28 00:00:00", "2022-06-28 23:59:59"], 
    # ["2022-06-29 00:00:00", "2022-06-29 23:59:59"], 
    # ["2022-06-30 00:00:00", "2022-06-30 23:59:59"], 
    # ["2022-07-01 00:00:00", "2022-07-01 23:59:59"], 
    # ["2022-07-02 00:00:00", "2022-07-02 23:59:59"], 
    # ["2022-07-03 00:00:00", "2022-07-03 23:59:59"], 
    # ["2022-07-04 00:00:00", "2022-07-04 23:59:59"], 
    # ["2022-07-05 00:00:00", "2022-07-05 23:59:59"], 
    # ["2022-07-06 00:00:00", "2022-07-06 23:59:59"], 
    # ["2022-07-07 00:00:00", "2022-07-07 23:59:59"], 
    # ["2022-07-08 00:00:00", "2022-07-08 23:59:59"], 
    # ["2022-07-09 00:00:00", "2022-07-09 15:00:00"]]