用于在python中排序多维数组的适当数据结构？ [英] appropriate data structure for sorting a multi dimensional array in python?

问题描述

对于我想组织成一个多维数组，然后排序的各种字符串（单词），我有三个数值（权重，计数，贡献）。为了做到这一点，我在一个字典中列出了列表，数值在列表中，字符串是关键字：

  print_dictionary [word] = [weight，count，contribution] 
  

我如何排序，先按升序排列然后按降序排列，通过贡献（列表中的第三个值），并显示排序列表的前10个项目。如何做到这一点？

例如，对于以下print_dictionary：

  print_dictionary [sam] = [2,7,1] 
 print_dictionary [sun] = [4,1,3] 
 print_dictionary [dog] = [1,3,2] 
  

我希望他们能够按升序排序捐款：

  Word：Weight：Count：Contribution：
 sam 2 7 1 
 dog 1 3 2 
 sun 4 1 3 
  

我看不到如何使用itemegetter：

  sorted（print_dictionary，key = itemgetter（2））
  

解决方案

您可以传递一个匿名函数作为排序的键。这使用多维dict的第三个成员作为关键：

 >>> d = {'a'：[1，4，7]，'b'：[2，3，9]，'c'：[3，2，8]} 
>>> （d，key = lambda x：d [x] [2]）：
 ...打印键，d [键] 
a [1，4，7] 
c [3，2，8] 
b [2，3，9] 
  

，使用 reverse = True 。要限制结果，请添加 [：N] ：

  d，key = lambda x：d [x] [2]，reverse = True）[：2] 
 
＃b [2，3，9] 
＃c [3，2 ，8] 
  

更多关于排序并在Python中进行排序。

I have three numeric values (weight, count, contribution) for various strings (words) that i would like to organise into one multidimensional array, and then sort. To do this, I made lists within a dictionary, where the numeric values are in the list and the string is the key:

print_dictionary[word] = [weight,count,contribution]

How can I sort, first in ascending order and then in descending order, by 'contribution' (the third value in the list), and show the first 10 items of the sorted list. How can I do this?

For example, for the following print_dictionary:

print_dictionary[sam] = [2,7,1]
print_dictionary[sun] = [4,1,3]
print_dictionary[dog] = [1,3,2]

I want to them be able to sort contribution in ascending order:

Word:   Weight:   Count:    Contribution:
sam     2         7         1
dog     1         3         2
sun     4         1         3

I don't see how itemegetter can be used for this:

sorted(print_dictionary, key=itemgetter(2))

解决方案

You can pass an anonymous function as the key to sorted. This uses the third member of the multi-dimensional dict as the key:

>>> d = {'a': [1, 4, 7], 'b': [2, 3, 9], 'c': [3, 2, 8]}
>>> for key in sorted(d, key=lambda x: d[x][2]):
...    print key, d[key]
a [1, 4, 7]
c [3, 2, 8]
b [2, 3, 9]

For descending order, use reverse=True. To limit the results, add [:N]:

sorted(d, key=lambda x: d[x][2], reverse=True)[:2]

# b [2, 3, 9]
# c [3, 2, 8]

More about sorted and sorting in Python.

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