如何获得当月的第一天？

Question

我正在为我的项目写一个脚本，我需要在在线网页中添加开始日期和结束日期。开始日期必须是当月的第一个日期，结束日期必须是昨天的日期

下面是预定义日期的代码。请帮忙解决。在下面，我必须手动添加从昨天到需要的天数，但需要自动查找以放置当月的第一天

daystostart = 6
daystoend = 1

# Time and Date

yesterday = dt.datetime.now() - dt.timedelta(days=daystostart)
StartDT = yesterday.strftime("%Y-%m-%d ") + "00:00:00"

yesterdayNightEnd = dt.datetime.now() - dt.timedelta(days=daystoend)
EndDT = yesterdayNightEnd.strftime("%Y-%m-%d ") + "23:59:59"

Answer 1

当月第一天

from datetime import datetime as dt
now = dt.now()

dt(now.year, now.month, 1)

Answer 2

from datetime import datetime

today = datetime.today().date()
first_day = today.replace(day=1)

Answer 3

from datetime import datetime
today = datetime.today()
first_day = datetime(today.year,today.month,1)
#2021-08-01 00:00:00