如何在 for 循环（日期时间）中步进一周（7 天）

Question

我有一个这样的 for 循环：

for mydate in daterange (startDate, endDate):

这每天都在增加。我希望这个步骤是一周。一个 hack 将跳过 6 天，但这太糟糕了。如何做到这一点？

def daterange(start_date, end_date):
    for n in range(int ((end_date - start_date).days)):
        yield start_date + timedelta(n)

Answer 1

您使用步长为 7 的范围对象并将其添加到开始日期：

import datetime

def daterange(startdate, enddate, steps=1): 
    """Yields dates in increments of steps days from startdate to enddate"""
    numdays = (enddate-startdate).days 
    for x in range (0, numdays, steps):
        yield startdate + datetime.timedelta(days = x)


today = datetime.datetime.today() 
end = today + datetime.timedelta(days=40)

print( list(daterange(today, end, 7)))

输出：

[datetime.datetime(2018, 9, 28, 19, 34, 26, 976681), 
 datetime.datetime(2018, 10, 5, 19, 34, 26, 976681), 
 datetime.datetime(2018, 10, 12, 19, 34, 26, 976681), 
 datetime.datetime(2018, 10, 19, 19, 34, 26, 976681), 
 datetime.datetime(2018, 10, 26, 19, 34, 26, 976681), 
 datetime.datetime(2018, 11, 2, 19, 34, 26, 976681)]

Answer 2

只需将步长添加到循环中：

from datetime import timedelta, date

def daterange(start_date, end_date):
     for n in range(0, int((end_date - start_date).days) + 1, 7):
         yield start_date + timedelta(n)

start_dt = date(2018, 9, 1)
end_dt = date(2018, 10, 30)
for dt in daterange(start_dt, end_dt):
    print(dt.strftime("%Y-%m-%d"))

输出：

如何在 for 循环（日期时间）中步进一周（7 天）

How to step one week (7 days) in a for loop (datetime)

python

python-datetime