python 獲取n天前的日期列表、獲取指定日期n天前的日期

獲取今天的前n天的日期列表

import datetime
def get_nday_list(n):
    import datetime
    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']

獲取指定時間的前n天的日期

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