Question

（这是每个人的一种假设情况。我更倾向于寻找方向而不是直接的过程，但是如果你能提供它们，真棒！）

所以，假设我们有一份运动员名单，我现在将使用花样滑冰运动员，因为我现在正处于冬季奥运会的膝盖深处。（因为那是我的第一直觉，所以我把它扔进字典里，不一定是这样。）

after_short_program = {
    '1': 'Evgeni Plushenko',
    '2': 'Evan Lysacek',
    '3': 'Daisuke Takahashi',
    '4': 'Nobunari Oda',
    '5': 'Stephane Lambiel'
}

所以在自由滑之后（我没有想到这一点），让我们说这些是积分榜。

after_free_skate = {
    '1': 'Evan Lysacek',
    '2': 'Daisuke Takahashi',
    '3': 'Evgeni Plushenko',
    '4': 'Stephane Lambiel',
    '5': 'Nobunari Oda',
}

所以，问题：

如何比较两组数据呢？ Evan Lysacek上升一个空间赢得金牌，Daisuke上升一个位置赢得银牌，Evgeni下移两个空位赢得铜牌。如果我要提供这些信息，我想说，“Evan（+1或向上移动一个），Evgeni（-2或向下移动两个）等等。”

Python中有没有办法从比较中提取这类数据？

Answer 1

我会使用运动员姓名作为你的决定中的关键。然后你可以更容易地找到他们的位置。类似的东西：

diff = {}
for (a, pos2) in after_free_skate.items():
     pos1 = after_short_program[a]
     diff[a] = pos2 - pos1

我希望它有所帮助

Answer 2

此解决方案以与最终位置相同的顺序打印结果如果地方未更改（+0）则打印如果您希望过滤掉那些，只需在打印前放置if diff:

>>> after_short_program = [
...     'Evgeni Plushenko',
...     'Evan Lysacek',
...     'Daisuke Takahashi',
...     'Nobunari Oda',
...     'Stephane Lambiel',
... ]
>>> 
>>> after_free_skate = [
...     'Evan Lysacek',
...     'Daisuke Takahashi',
...     'Evgeni Plushenko',
...     'Stephane Lambiel',
...     'Nobunari Oda',
... ]
>>> 
>>> for i,item in enumerate(after_free_skate):
...     diff = after_short_program.index(item)-i
...     print "%s (%+d)"%(item,diff)
...     
... 
Evan Lysacek (+1)
Daisuke Takahashi (+1)
Evgeni Plushenko (-2)
Stephane Lambiel (+1)
Nobunari Oda (-1)

正如普瓦森指出的那样，如果你的秒表不够好，你可能会得到平局。因此，此修改使用dicts而不是列表。排名的顺序仍然保留

>>> from operator import itemgetter
>>> 
>>> after_short_program = {
...     'Evgeni Plushenko':1,
...     'Evan Lysacek':2,
...     'Daisuke Takahashi':3,
...     'Stephane Lambiel':4,
...     'Nobunari Oda':5,
... }
>>> 
>>> after_free_skate = {
...     'Evan Lysacek':1,
...     'Daisuke Takahashi':2,
...     'Evgeni Plushenko':3,
...     'Stephane Lambiel':4,   # These are tied
...     'Nobunari Oda':4,       # at 4th place
... }
>>> 
>>> for k,v in sorted(after_free_skate.items(),key=itemgetter(1)):
...     diff = after_short_program[k]-v
...     print "%s (%+d)"%(k,diff)
...     
... 
Evan Lysacek (+1)
Daisuke Takahashi (+1)
Evgeni Plushenko (-2)
Nobunari Oda (+1)
Stephane Lambiel (+0)
>>>

如果第二个词典中的键可能不在第一个词中，你可以做这样的事情

for k,v in sorted(after_free_skate.items(),key=itemgetter(1)):
    try:
        diff = after_short_program[k]-v
        print "%s (%+d)"%(k,diff)
    except KeyError:
        print "%s (new)"%k

Answer 3

一种方法是翻转键和值，然后取出差异，即：

for k, v in after_free_skate.items():
   print 'k', v - after_short_program[k]

Answer 4

我个人使用列表，因为它们自然适合存储“位置”信息......以下是采用列表的功能相当的方法：

###_* input data
after_short_program = [
    'Evgeni Plushenko',
    'Evan Lysacek',
    'Daisuke Takahashi',
    'Nobunari Oda',
    'Stephane Lambiel'
    ]
after_free_skate = [
    'Evan Lysacek',
    'Daisuke Takahashi',
    'Evgeni Plushenko',
    'Stephane Lambiel',
    'Nobunari Oda'
    ]

## combine
all_athletes = set(after_short_program + after_free_skate)

###_* import libraries, define functions
from operator import add, sub
from functools import partial

def tryit(f,*args):
    try: return f(*args)
    except: return None
def compose(f,g): ## available in functional library
    return lambda x: f(g(x))

###_* apply functions
## original and new positions for each athlete
## I usually wrap list.index() in a try-except clause
pos = [(x,{'orig':tryit(compose(partial(add,1),after_short_program.index),x),
           'new':tryit(compose(partial(add,1),after_free_skate.index),x)})
       for i,x in enumerate(all_athletes)]

## calculate the changes (now edited to sort by final position)
changes = [(x[0],tryit(sub,x[1]['orig'],x[1]['new']))
           for x in sorted(pos,key=lambda x: x[1]['new'])]

输出如下：

>>> changes
[('Evan Lysacek', 1), ('Daisuke Takahashi', 1), ('Evgeni Plushenko', -2), ('Stephane Lambiel', 1), ('Nobunari Oda', -1)]

Answer 5

我会将名称作为键，将位置作为值，将位置设为整数：

after_short_program = {
    '1': 'Evgeni Plushenko',
    '2': 'Evan Lysacek',
    '3': 'Daisuke Takahashi',
    '4': 'Nobunari Oda',
    '5': 'Stephane Lambiel'
}

after_free_skate = {
    '1': 'Evan Lysacek',
    '2': 'Daisuke Takahashi',
    '3': 'Evgeni Plushenko',
    '4': 'Stephane Lambiel',
    '5': 'Nobunari Oda',
}

after_short_program_swap = {}
for k,v in after_short_program.iteritems():
   after_short_program_swap[v]=int(k)

after_free_skate_swap = {}
for k,v in after_free_skate.iteritems():
    after_free_skate_swap[v]=int(k)

然后代码更简单：

moved = {}
for key in after_short_program_swap:
    moved[key] = after_short_program_swap[key] - after_free_skate_swap[key]

print moved

打印：

<'Evan Lysacek'：1，'Nobunari Oda'：-1，'Evgeni Plushenko'： - 2，'Stephane Lambiel'：1，'Daisuke Takahashi'：1}

在@gnibbler之后打印出奖牌顺序：

from operator import itemgetter
print '\n'.join('%s (%+d)' % (k,moved[k]) for k,v in sorted(after_free_skate_swap.items(),key=itemgetter(1)))

Evan Lysacek（+1）

Daisuke Takahashi（+1）

Evgeni Plushenko（-2）

Stephane Lambiel（+1）

Nobunari Oda（-1）

Python中的位置比较

5 个答案: