Python取周的相关信息的几个函数

主要包括：获取指定日期对应哪一年的第几周、获取当前日期对应哪一年的第几周、获取当前日期这一周的第一天的日期、获取指定周的第一天日期。
/Users/nisj/PycharmProjects/EsDataProc/bi-static/getWeekInfo.py

# -*- coding=utf-8 -*-
import datetime

def getYearWeek(strdate):
    date = datetime.datetime.strptime(strdate, '%Y-%m-%d')
    YearWeek = date.isocalendar()
    return YearWeek

def getNowYearWeek():
    # 当前时间年第几周的计算
    timenow = datetime.datetime.now()
    NowYearWeek = timenow.isocalendar()
    return NowYearWeek

def getDayInweekMonday():
    week_num = datetime.datetime.now().weekday()
    Monday = datetime.datetime.now() + datetime.timedelta(days=-week_num)
    Monday = str(Monday)[0:10]
    return Monday

# weekflag格式为"2016#53"（即2016年第53周）
def getWeekFirstday(weekflag):
    year_str = weekflag[0:4]  # 取到年份
    week_str = weekflag[5:]  # 取到周
    if int(week_str)>=53:
        Monday = "Error,Week Num greater than 53!"
    else:
        yearstart_str = year_str + '0101'  # 当年第一天
        yearstart = datetime.datetime.strptime(yearstart_str, '%Y%m%d')  # 格式化为日期格式
        yearstartcalendarmsg = yearstart.isocalendar()  # 当年第一天的周信息
        yearstartweekday = yearstartcalendarmsg[2]
        yearstartyear = yearstartcalendarmsg[0]
        if yearstartyear < int(year_str):
            daydelat = (8 - int(yearstartweekday)) + (int(week_str) - 1) * 7
        else:
            daydelat = (8 - int(yearstartweekday)) + (int(week_str) - 2) * 7
        Monday = (yearstart + datetime.timedelta(days=daydelat)).date()
    return Monday

if __name__ == '__main__':
    strdate = '2017-01-01'
    print getYearWeek(strdate)
    print getNowYearWeek()
    print getDayInweekMonday()
    # 输出2014年第35周的开始时间
    print getWeekFirstday('2019#1')

测试结果：

/usr/bin/python /Users/nisj/PycharmProjects/EsDataProc/bi-static/getWeekInfo.py
(2016, 52, 7)
(2017, 1, 5)
2017-01-02
2018-12-31

Process finished with exit code 0