英文:
How to implement SQL ORDER BY like funtionality in python?
问题
我有一个类似这样的对象列表
time_slots = ['<TimeSlot: capacity: 1, number: 5>',
'<TimeSlot: Room: capacity: 3, number: 2>',
'<TimeSlot: capacity: 4, number: 1>',
'<TimeSlot: capacity: 4, number: 6>',
'<TimeSlot: capacity: 4, number: 1>',
'<TimeSlot: capacity: 4, number: 3>']
我想根据number和capacity对上述对象进行排序。
基本上，我想实现这个：
ORDER BY number, capacity;
我可以通过类似以下方式访问每个对象的属性：
time_slots[i].number
我需要在Python中实现这个逻辑。有人可以帮我吗？
编辑：这是实际问题的简化版本。请参阅实际问题
stackoverflow.com/q/75664227/20443528
英文:
I have a list of objects like this
time_slots = ['<TimeSlot: capacity: 1, number: 5>',
'<TimeSlot: Room: capacity: 3, number: 2>',
'<TimeSlot: capacity: 4, number: 1>',
'<TimeSlot: capacity: 4, number: 6>',
'<TimeSlot: capacity: 4, number: 1>',
'<TimeSlot: capacity: 4, number: 3>']
I want to sort the above object on the basis of number and capacity.
Basically, I want to implement this-
ORDER BY number, capacity;
I can access the properties of every object by using something like-
time_slots[i].number
I have to implement this logic in python. Can someone please help me with this?
Edit: This is a simplified version of the actual problem. Please see the actual problem
stackoverflow.com/q/75664227/20443528
答案1
得分: 2
你可以将一个方法传递给 sorted 函数，以指定要按哪些属性排序并返回为元组。类似以下的代码应该可以工作：
sorted(time_slots, key=lambda x: (x.number, x.capacity))
英文:
You can pass a method to the sorted function to specify the attributes to sort by returned in a tuple. Something like this should work:
sorted(time_slots, key=lambda x: (x.number, x.capacity))
答案2
得分: 0
你必须包含 quotes 以使其成为有效的Python代码：
l=['<TimeSlot: capacity: 4, number: 1>', '<TimeSlot: Room: capacity: 3, number: 2>', '<TimeSlot: capacity: 4, number: 6>','<TimeSlot: capacity: 4, number: 1>', '<TimeSlot: capacity: 1, number: 5>', '<TimeSlot: capacity: 4, number: 3>']
sorted(l,key=lambda x:x.split('capacity')[1][2])
解释：
我们通过关键字 capacity 进行分割，分割后的列表中将会有 2 个元素。然后您必须对它们进行索引以获取其中的数值。
英文:
You have to include quotes to make it a valid python:
l=['<TimeSlot: capacity: 4, number: 1>', '<TimeSlot: Room: capacity: 3, number: 2>', '<TimeSlot: capacity: 4, number: 6>','<TimeSlot: capacity: 4, number: 1>', '<TimeSlot: capacity: 1, number: 5>', '<TimeSlot: capacity: 4, number: 3>']
sorted(l,key=lambda x:x.split('capacity')[1][2])
#
['<TimeSlot: capacity: 1, number: 5>',
'<TimeSlot: Room: capacity: 3, number: 2>',
'<TimeSlot: capacity: 4, number: 1>',
'<TimeSlot: capacity: 4, number: 6>',
'<TimeSlot: capacity: 4, number: 1>',
'<TimeSlot: capacity: 4, number: 3>']
Explanation:
We are splitting by 'capacity' keyword, there will be 2 elements in the list formed after split. Then you have to index them to get the numeric value from it.
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