做数据分析绕不开“季度末”，那么Python中怎么获得当前季度最后一天的日期呢？

from datetime import datetime as dt
def getql():
    today=dt.now()
    quarter = (today.month-1)/3+1
    if quarter == 1:
        return dt(today.year,3,31)
    elif quarter == 2:
        return dt(today.year,6,30)
    elif quarter == 3:
        return dt(today.year,9,30)
    else:
        return dt(today.year,12,31)

这个办法虽然笨，但也是相当准确的。哈哈哈！

闲话少叙，直接上代码

from datetime import datetime
def getlastseason(today):
    today = datetime.strptime(today, '%Y%m%d')
    quarter = (today.month - 1) / 3 + 1
    if quarter == 1:
        return datetime(today.year - 1, 12, 31).strftime('%Y%m%d')
    elif quarter == 2:
        return datetime(today.year, 3, 31).strftime('%Y%m%d')
    elif quarter == 3:
        return datetime(today.year, 6, 30).strftime('%Y%m%d')
    else:
        return datetime(today.year, 9, 30).strftime('%Y%m%d')

这个函数的参数是字符串日期，比如'20180101'，返回的也是字符串的日期，函数调用如下：

/**
 * 根据 年份 和 季度  获取 季度 第一天 和 季度 最后 一天
 * @param year
 * @param quarter
 */
function getQuartorStartDate(year,quarter) {
	let startMonth = 1;
	if(quarter == 1){
		startMonth = 1;
	}else if (quarter == 2){
		startMonth = 4;
	}else if (quarter == 3){
		startMonth = 7;
	}else if (quarter == 4){
		startMonth = 10;
	}
	let endMonth = startMonth + 2;
	if (quarter == 0){
		endMonth = 12
	}
	const startDate = year+"-"+formatDate(startMonth)+'-01';
	const endDate = year + '-' + formatDate(endMonth) + '-' +new Date(year,endMonth,0).getDate()
	console.log(startDate,endDate)
	return {startDate,endDate}
}

//格式化月和日为MM、dd
function formatDate(value){
	if(value < 10){
		value = "0" + value;
	}
	return value;
}

//获取本季度的第一天
Console.WriteLine(DateTime.Now.AddMonths(0 - ((DateTime.Now.Month - 1) % 3)).ToString("yyyy-MM-01"));


//获取本季度的最后一天
Console.WriteLine(DateTime.Parse(DateTime.Now.AddMonths(3 - ((DateTime.Now.Month - 1) % 3)).ToString("yyyy-MM-01")).AddDays(-1).ToShortDateString());


 //获取下一个季度第一天和最后一天

Console.WriteLine(DateTime.Now.AddMonths(3 - ((DateTime.Now.Month - 1) % 3)).ToString("yyyy-MM-01"));
Console.WriteLine(DateTime.Parse(DateTime.Now.AddMonths(6-((DateTime.Now.Month-1)%3)).ToString("yyyy-MM-01")).AddDays(-1).ToShortDateString());


//获取上一个季度第一天和最后一天

Console.WriteLine(DateTime.Now.AddMonths(-3 - ((DateTime.Now.Month - 1) % 3)).ToString("yyyy-MM-01"));

Console.WriteLine(DateTime.Parse(DateTime.Now.AddMonths(0 - ((DateTime.Now.Month - 1) % 3)).ToString("yyyy-MM-01")).AddDays(-1).ToShortDateString());