Python - 列表映射

Question

我有几个列表想要一起映射，但我无法完全弄清楚如何去做。

我正在抓取赛马结果的实时直播。该提要仅列出一次路线/时间以及三匹马及其位置（前三名）或四匹马和空白（即“”）位置（如果比赛被放弃）。这些是我的清单：

course, time, abandoned, horses, position

清单按顺序排列。

course、time 和 abandoned 都具有完全相同数量的元素（abandoned 是布尔值列表，True 表示比赛被放弃）。

horses 是 (3 * 未放弃比赛的数量) + (4 * 放弃比赛的数量) 马匹的列表。

position 是马匹位置的列表。如果比赛被放弃，位置将为“”，否则为“1”、“2”、“3”（字符串！）。

示例列表：

没有放弃比赛

course = ["Course A", "Course A", "Course B"] #there were two races at course A
times  = ["00:00", "01:00", "15:00"] #Race 1 at Course A was at 00:00, race 2 at course                   A was at 01:00
horses = ["HorseA 1", "HorseA 2", "HorseA 3", "HorseA 4", "HorseA 5", "HorseA 6", "HorseB 1", "HorseB 2", "HorseB 3"] #There are three horses per race

positions = ["1","2","3","1","2","3","1","2","3"]

因此，在 00:00 比赛的 A 球场，“HorseA 1”获得第一名，“HorseA 2”获得第二名，“HorseA 3”获得第三名。

有一场被放弃的比赛

courses = ["CourseX", "CourseX", "CourseY"]
times   = ["01:00",  "02:00", "01:00"]
abandoned = [False, False, True]
horses = ["X1", "X2", "X3", "X4", "X5", "X6", "Y1", "Y2", "Y3", "Y4"]
positions = ["1","2","3","1","2","3","","","",""]

因此，在 CourseX 上有两场比赛，但在 CourseY 上的比赛被放弃了。

我想要最终得到的是一个元组列表，如下所示：

[(A Race Course, 00:00, False, Horsey, 1), (A Race Course, 00:00, False, Horsey 2, 2) ... ]

我不知道该怎么做，有建议吗？

干杯，

皮特

Answer 1

>>> class s:
    courses = ["CourseX", "CourseX", "CourseY"]
    times   = ["01:00",  "02:00", "01:00"]
    abandoned = [False, False, True]
    horses = ["X1", "X2", "X3", "X4", "X5", "X6", "Y1", "Y2", "Y3", "Y4"]
    positions = ["1","2","3","1","2","3","","","",""]

>>> def races(courses, times, abandoned, horses, positions):
    z = zip(horses, positions)
    for course, time, stopped in zip(courses, times, abandoned):
        for _ in range(4 if stopped else 3):
            horse, pos = next(z)
            yield course, time, stopped, horse, pos


>>> print(*races(s.courses, s.times, s.abandoned, s.horses, s.positions), sep='\n')
('CourseX', '01:00', False, 'X1', '1')
('CourseX', '01:00', False, 'X2', '2')
('CourseX', '01:00', False, 'X3', '3')
('CourseX', '02:00', False, 'X4', '1')
('CourseX', '02:00', False, 'X5', '2')
('CourseX', '02:00', False, 'X6', '3')
('CourseY', '01:00', True, 'Y1', '')
('CourseY', '01:00', True, 'Y2', '')
('CourseY', '01:00', True, 'Y3', '')
('CourseY', '01:00', True, 'Y4', '')

Answer 2

您想要使用 zip() 函数这。

如果没有更多关于马的外观信息，我实际上无法给您一个例子。是[H1, h2, h3, "", h5, h6, h7, h8, h9, h10, ""]吗？

首先，您需要压缩相同长度的项目：

races = zip(course, time, abandoned)

然后（取决于您不清楚的马匹结构）您将需要使用列表理解将一个比赛项目附加到每匹马结果中。首先将马匹列表划分为 horses_in_race 列表，然后将其与您的 zip 和列表组合一起使用可能会更容易。

如果问题更完整，我可以提供更好的答案。

Answer 3

def expand(abandoned,seq):
    for was_abandoned,elt in zip(abandoned,seq):
        if was_abandoned:
            for _ in range(4): yield elt
        else:
            for _ in range(3): yield elt            

course=['A Race Course','B Race Course']
time=['00:00','01:00']
abandoned=[False,True]
horses=['Horsey-{0}'.format(n) for n in range(8)]
position=['1','2','3','','','','']

result=[(c,t,a,h,p) for (c,t,a),h,p in
        zip(expand(abandoned,zip(course,time,abandoned)),horses,position)]
print(result)

产量

[('赛马场', '00:00', False,
'Horsey-0', '1'), ('赛马场',
'00:00', False, 'Horsey-1', '2'), ('A
赛马场', '00:00', False,
'Horsey-2', '3'), ('B 赛马场',
'01:00', True, 'Horsey-3', ''), ('B
赛马场', '01:00', True,
'Horsey-4', ''), ('B 赛马场',
'01:00', True, 'Horsey-5', ''), ('B
赛马场', '01:00', True,
'Horsey-6', '')]