基于自定义排序键的排序

huangapple
go评论163阅读模式
英文:

Sorting based on custom sort key

问题

我有一个接收这两个参数的Python函数：

  1.     list = [
  2.                 {"id": "5", "name": "tomato", "value": 3},
  3.                 {"id": "2", "name": "banana", "value": 2},
  4.                 {"id": "4", "name": "tomato", "value": 2},
  5.                 {"id": "1", "name": "banana", "value": 1.5},
  6.                 {"id": "8", "name": "peas", "value": 1.5},
  7.                 {"id": "7", "name": "peas", "value": 0.5}
  8.             ]
  10.     "importance"={
  11.                 "tomato": 2,
  12.                 "banana": 1,
  13.                 "peas": 6
  14.                }
  16. 我基于值预先对列表进行了排序，但现在我想根据重要性在相同值的基础上进行排序，使最终结果如下：
  18. ```python
  19.     list = [
  20.             {"id": "5", "name": "tomato", "value": 3},
  21.             {"id": "4", "name": "tomato", "value": 2},
  22.             {"id": "2", "name": "banana", "value": 2},
  23.             {"id": "8", "name": "peas", "value": 1.5},
  24.             {"id": "1", "name": "banana", "value": 1.5},
  25.             {"id": "7", "name": "peas", "value": 0.5}
  26.         ]

如何使用自定义排序函数实现这一点？还是有更好的方法吗？

英文:

I have a python function that receives this 2 arguments:

  1. list = [
  2.             {"id": "5", "name": "tomato", "value": 3},
  3.             {"id": "2", "name": "banana", "value": 2},
  4.             {"id": "4", "name": "tomato", "value": 2},
  5.             {"id": "1", "name": "banana", "value": 1.5},
  6.             {"id": "8", "name": "peas", "value": 1.5},
  7.             {"id": "7", "name": "peas", "value": 0.5}
  8.         ]
  11. "importance"={
  12.             "tomato": 2,
  13.             "banana": 1,
  14.             "peas": 6
  15.            }

I pre ordered the list based on value but now I want to order on the same value floor according to importance so it would look like in the end:

  1. list = [
  2.         {"id": "5", "name": "tomato", "value": 3},
  3.         {"id": "4", "name": "tomato", "value": 2},
  4.         {"id": "2", "name": "banana", "value": 2},
  5.         {"id": "8", "name": "peas", "value": 1.5},
  6.         {"id": "1", "name": "banana", "value": 1.5},
  7.         {"id": "7", "name": "peas", "value": 0.5}
  8.     ]

How can I do this using custom sort functions? Or is there any better way to do it?

答案1

得分: 1

.sort 和 sorted 函数接受一个 key 参数，该参数可以返回一个数字或数字元组。输出将按照元组的第一个元素，然后是第二个元素等进行排序。这样，你可以根据所有要求进行排序。

  1. l = [
  2.     {"id": "5", "name": "tomato", "value": 3},
  3.     {"id": "2", "name": "banana", "value": 2},
  4.     {"id": "4", "name": "tomato", "value": 2},
  5.     {"id": "1", "name": "banana", "value": 1.5},
  6.     {"id": "8", "name": "peas", "value": 1.5},
  7.     {"id": "7", "name": "peas", "value": 0.5}
  8. ]
  10. importance = {
  11.     "tomato": 2,
  12.     "banana": 1,
  13.     "peas": 6
  14. }
  16. print(sorted(l, key=lambda x: (x["value"], importance[x["name"]]), reverse=True))

输出:

  1. [
  2.     {'id': '5', 'name': 'tomato', 'value': 3},
  3.     {'id': '4', 'name': 'tomato', 'value': 2},
  4.     {'id': '2', 'name': 'banana', 'value': 2},
  5.     {'id': '8', 'name': 'peas', 'value': 1.5},
  6.     {'id': '1', 'name': 'banana', 'value': 1.5},
  7.     {'id': '7', 'name': 'peas', 'value': 0.5}
  8. ]

注意：使用此代码，不需要预先按值进行排序 - 两个键都会被考虑在内。

英文:

.sort and sorted functions accept a key argument, which can return a number or a tuple of numbers. Output will be sorted by first element of such tuple, then second etc. This way you can sort according to all the requirements you have.

  1. l = [
  2.             {"id": "5", "name": "tomato", "value": 3},
  3.             {"id": "2", "name": "banana", "value": 2},
  4.             {"id": "4", "name": "tomato", "value": 2},
  5.             {"id": "1", "name": "banana", "value": 1.5},
  6.             {"id": "8", "name": "peas", "value": 1.5},
  7.             {"id": "7", "name": "peas", "value": 0.5}
  8.         ]
  11. importance = {
  12.             "tomato": 2,
  13.             "banana": 1,
  14.             "peas": 6
  15.            }
  17. print(sorted(l, key = lambda x: (x["value"], importance[x["name"]]), reverse=True))

Output:

  1. [
  2.     {'id': '5', 'name': 'tomato', 'value': 3}, 
  3.     {'id': '4', 'name': 'tomato', 'value': 2}, 
  4.     {'id': '2', 'name': 'banana', 'value': 2}, 
  5.     {'id': '8', 'name': 'peas', 'value': 1.5}, 
  6.     {'id': '1', 'name': 'banana', 'value': 1.5}, 
  7.     {'id': '7', 'name': 'peas', 'value': 0.5}
  8. ]

Note: With this code, there is no need to pre-sort according to just value first - both keys are taken into account.

答案2

得分: 1

使用离散函数返回排序键，您可以这样做：

  1. import json
  3. _list = [
  4.     {"id": "5", "name": "tomato", "value": 3},
  5.     {"id": "2", "name": "banana", "value": 2},
  6.     {"id": "4", "name": "tomato", "value": 2},
  7.     {"id": "1", "name": "banana", "value": 1.5},
  8.     {"id": "8", "name": "peas", "value": 1.5},
  9.     {"id": "7", "name": "peas", "value": 0.5}
  10. ]
  12. importance = {
  13.     "tomato": 2,
  14.     "banana": 1,
  15.     "peas": 6
  16. }
  18. def key(e):
  19.     # 使用负值以避免需要反转排序
  20.     return -e['value'], -importance[e['name']]
  22. _list.sort(key=key)
  24. print(json.dumps(_list, indent=2))

输出结果:

  1. [
  2.   {
  3.     "id": "5",
  4.     "name": "tomato",
  5.     "value": 3
  6.   },
  7.   {
  8.     "id": "4",
  9.     "name": "tomato",
  10.     "value": 2
  11.   },
  12.   {
  13.     "id": "2",
  14.     "name": "banana",
  15.     "value": 2
  16.   },
  17.   {
  18.     "id": "8",
  19.     "name": "peas",
  20.     "value": 1.5
  21.   },
  22.   {
  23.     "id": "1",
  24.     "name": "banana",
  25.     "value": 1.5
  26.   },
  27.   {
  28.     "id": "7",
  29.     "name": "peas",
  30.     "value": 0.5
  31.   }
  32. ]
英文:

Using a discrete function to return the sort key, you can do this:

  1. import json
  3. _list = [
  4.     {"id": "5", "name": "tomato", "value": 3},
  5.     {"id": "2", "name": "banana", "value": 2},
  6.     {"id": "4", "name": "tomato", "value": 2},
  7.     {"id": "1", "name": "banana", "value": 1.5},
  8.     {"id": "8", "name": "peas", "value": 1.5},
  9.     {"id": "7", "name": "peas", "value": 0.5}
  10. ]
  13. importance = {
  14.     "tomato": 2,
  15.     "banana": 1,
  16.     "peas": 6
  17. }
  20. def key(e):
  21.     # use -ve values to avoid the need for reversing the sort
  22.     return -e['value'], -importance[e['name']]
  25. _list.sort(key=key)
  27. print(json.dumps(_list, indent=2))

Output:

  1. [
  2.   {
  3.     "id": "5",
  4.     "name": "tomato",
  5.     "value": 3
  6.   },
  7.   {
  8.     "id": "4",
  9.     "name": "tomato",
  10.     "value": 2
  11.   },
  12.   {
  13.     "id": "2",
  14.     "name": "banana",
  15.     "value": 2
  16.   },
  17.   {
  18.     "id": "8",
  19.     "name": "peas",
  20.     "value": 1.5
  21.   },
  22.   {
  23.     "id": "1",
  24.     "name": "banana",
  25.     "value": 1.5
  26.   },
  27.   {
  28.     "id": "7",
  29.     "name": "peas",
  30.     "value": 0.5
  31.   }
  32. ]

huangapple
  • 本文由 发表于 2023年5月25日 16:47:51
  • 转载请务必保留本文链接：https://go.coder-hub.com/76330423.html
  • custom-sort
  • python
  • sorting
匿名

发表评论

匿名网友

:?: :razz: :sad: :evil: :!: :smile: :oops: :grin: :eek: :shock: :???: :cool: :lol: :mad: :twisted: :roll: :wink: :idea: :arrow: :neutral: :cry: :mrgreen:

确定