我怎样才能获得两天之间的所有日子？

Question

我需要两天之间的所有工作日.

例:

Wednesday - Friday  = Wednesday, Thursday, Friday  
        3 - 5       = 3, 4, 5

 Saturday - Tuesday = Saturday, Sunday, Monday, Tuesday
        6 - 2       = 6, 7, 1, 2

我很确定有一个聪明的算法来解决这个问题.我能想到的唯一算法是使用循环或if语句.

必须有一种优雅的方法来解决这个问题.我在工作日使用数字1-7,但0-6也很好.

我能想到的最好的:

def between(d1, d2):
     alldays = [0,1,2,3,4,5,6,0,1,2,3,4,5,6]    # or range(7) * 2
     offset = 8 if d1 > d2 else 1
     return alldays[d1:d2 + offset]

between(0, 4)
# [0,1,2,3,4]

between(5,2)
# [5,6,0,1,2]

Answer 1

怎么样(在伪代码中):

weekday[] = {"Mon" .. "Sun"}
for(i = wkday_start; (i % 7) != wkday_end; i = (i+1) % 7)
    printf("%s ", weekday[i]);

它的工作方式类似于循环缓冲区,wkday_start是从(从0开始)开始的索引,wkday_end是结束索引.

希望这可以帮助

乔治.

Answer 2

>>> def weekdays_between(s, e):
...     return [n % 7 for n in range(s, e + (1 if e > s else 8))]
... 
>>> weekdays_between(2, 4)
[2, 3, 4]
>>> weekdays_between(5, 1)
[5, 6, 0, 1]

如果你必须从/转换到实际天数,它会更复杂一些.

>>> days = 'Mon Tue Wed Thu Fri Sat Sun'.split()
>>> days_1 = {d: n for n, d in enumerate(days)}
>>> def weekdays_between(s, e): 
...     s, e = days_1[s], days_1[e]
...     return [days[n % 7] for n in range(s, e + (1 if e > s else 8))]
... 
>>> weekdays_between('Wed', 'Fri')
['Wed', 'Thu', 'Fri']
>>> weekdays_between('Sat', 'Tue')
['Sat', 'Sun', 'Mon', 'Tue']