Python-获取当前月的前x月月份日期

"""
获取当前月的前x月月份日期
"""
import datetime

def getTheMonth(date, n):
    month = date.month
    year = date.year
    for i in range(n):
        if month == 1:
            year -= 1
            month = 12
        else:
            month -= 1
    return datetime.date(year, month, 1).strftime('%Y-%m')


date = datetime.datetime.today()
single_time_new = getTheMonth(date, 5)
single_time_old = getTheMonth(date, 6)

import datetime

# 根据开始日期、结束日期返回这段时间里所有天的集合
def getDatesByTimes(sDateStr, eDateStr):
    list = []
    datestart = datetime.datetime.strptime(sDateStr, '%Y-%m-%d')
    dateend = datetime.datetime.strptime(eDateStr, '%Y-%m-%d')
    list.append(datestart.strftime('%Y-%m-%d'))
    while datestart < dateend:
        datestart += datetime.timedelta(days=1)
        list.append(datestart.strftime('%Y-%m-%d'))
    return list


#上一天的时间
def getYesterday():
    yesterday = datetime.date.today() + datetime.timedelta(-2)
    return yesterday


#现在时间
def getnowYesterday():
    nowday = datetime.date.today() + datetime.timedelta(-1)
    return nowday



#获取前1天或N天的日期，beforeOfDay=1：前1天；beforeOfDay=N：前N天
def getdate(beforeOfDay):
    today = datetime.datetime.now()
    # 计算偏移量
    offset = datetime.timedelta(days=-beforeOfDay)
    # 获取想要的日期的时间
    re_date = (today + offset).strftime('%Y-%m-%d')
    return re_date


#获取前一周的所有日期(weeks=1)，获取前N周的所有日期(weeks=N)
def getBeforeWeekDays(weeks=1):
    # 0,1,2,3,4,5,6,分别对应周一到周日
    weeks=1
    week = datetime.datetime.now().weekday()
    days_list = []
    start = 7 * weeks +  week
    end = week
    for index in range(start, end, -1):
        day =getdate(index) 
        days_list.append(day)
    return days_list


#计算两个日期相差天数，自定义函数名，和两个日期的变量名。
def Caltime(date1,date2):
    #%Y-%m-%d为日期格式，其中的-可以用其他代替或者不写，但是要统一，同理后面的时分秒也一样；可以只计算日期，不计算时间。
    #date1=time.strptime(date1,"%Y-%m-%d %H:%M:%S") 
    #date2=time.strptime(date2,"%Y-%m-%d %H:%M:%S")
    date1=time.strptime(date1,"%Y/%m/%d")
    date2=time.strptime(date2,"%Y/%m/%d")
    #根据上面需要计算日期还是日期时间，来确定需要几个数组段。下标0表示年，小标1表示月，依次类推...
    #date1=datetime.datetime(date1[0],date1[1],date1[2],date1[3],date1[4],date1[5])
    #date2=datetime.datetime(date2[0],date2[1],date2[2],date2[3],date2[4],date2[5])
    date1=datetime.datetime(date1[0],date1[1],date1[2])
    date2=datetime.datetime(date2[0],date2[1],date2[2])
    #返回两个变量相差的值，就是相差天数
    print((date2-date1).days)#将天数转成int型
    return(date2-date1)

from datetime import timedelta
import datetime
import calendar


def gen_dates(b_date, days):
    day = timedelta(days=1)
    for i in range(days):
        yield b_date + day*i


def get_date_list(start_date, end_date):
    if start_date is not None:
        start = datetime.datetime.strptime(start_date, "%Y-%m-%d")
    if end_date is None:
        end = datetime.datetime.now()
    else:
        end = datetime.datetime.strptime(end_date, "%Y-%m-%d")
    data = []
    for d in gen_dates(start, ((end-start).days + 1)):    # 29 + 1
        data.append(d.strftime("%Y-%m-%d"))
    return data


def getMonthFirstDayAndLastDay(year=None, month=None):
    if year:
        year = int(year)
    else:
        year = datetime.date.today().year
    if month:
        month = int(month)
    else:
        month = datetime.date.today().month
    # 获取当月第一天的星期和当月的总天数
    firstDayWeekDay, monthRange = calendar.monthrange(year, month)
    # 获取当月的第一天
    firstDay = datetime.date(year=year, month=month, day=1)
    firstDay = firstDay.strftime('%Y-%m-%d')
    lastDay = datetime.date(year=year, month=month, day=monthRange)
    lastDay = lastDay.strftime('%Y-%m-%d')
    return firstDay,lastDay


def first_last(time):
    year = time[:4]
    month = time[4:6]
    firstday = getMonthFirstDayAndLastDay(year, month)[0]
    lastday = getMonthFirstDayAndLastDay(year, month)[1]
    return get_date_list(firstday,lastday)


def main():
    time="202002"
    print(first_last(time))

 

本文地址：https://blog.csdn.net/qq_39142369/article/details/110874495