Python 生成日期列表

import datetime

def create_assist_date(datestart = None,dateend = None):
	# 创建日期辅助表

	if datestart is None:
		datestart = '2016-01-01'
	if dateend is None:
		dateend = datetime.datetime.now().strftime('%Y-%m-%d')

	# 转为日期格式
	datestart=datetime.datetime.strptime(datestart,'%Y-%m-%d')
	dateend=datetime.datetime.strptime(dateend,'%Y-%m-%d')
	date_list = []
	date_list.append(datestart.strftime('%Y-%m-%d'))
	while datestart<dateend:
		# 日期叠加一天
	    datestart+=datetime.timedelta(days=+1)
	    # 日期转字符串存入列表
	    date_list.append(datestart.strftime('%Y-%m-%d'))
	print(date_list)


if __name__ == '__main__':
	create_assist_date("2018-06-28")

['2018-06-28', '2018-06-29', '2018-06-30', '2018-07-01', '2018-07-02', '2018-07-03', '2018-07-04', '2018-07-05', '2018-07-06']

import datetime

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

a = get_nday_list(7)
print(a)
['2017-02-22', '2017-02-23', '2017-02-24', '2017-02-25', '2017-02-26', '2017-02-27', '2017-02-28']

import datetime
def get_day_nday_ago(date,n):
    t = time.strptime(date, "%Y-%m-%d")
    y, m, d = t[0:3]
    Date = str(datetime.datetime(y, m, d) - datetime.timedelta(n)).split()
    return Date[0]

# 示例
a=get_day_nday_ago('2017-02-11',7)
print a
2017-02-04