基于子数组第二个元素的Python排序多维数组
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Python Sort Multidimensional Array Based on 2nd Element of Subarray
提问by Federico Capello
I have an array like this:
我有一个这样的数组：
[['G', 10], ['A', 22], ['S', 1], ['P', 14], ['V', 13], ['T', 7], ['C', 0], ['I', 219]]
I'd like to sort it based on the 2nd element in descending order. An ideal output would be:
我想根据降序的第二个元素对其进行排序。理想的输出是：
[['I', 219], ['A', 22], ['P', 14], ... ]
采纳答案by falsetru
list.sort, sortedaccept optional keyparameter. keyfunction is used to generate comparison key.
list.sort,sorted接受可选key参数。key函数用于生成比较键。
>>> sorted(lst, key=lambda x: x[1], reverse=True)
[['I', 219], ['A', 22], ['P', 14], ['V', 13], ['G', 10], ...]
>>> sorted(lst, key=lambda x: -x[1])
[['I', 219], ['A', 22], ['P', 14], ['V', 13], ['G', 10], ...]
>>> import operator
>>> sorted(lst, key=operator.itemgetter(1), reverse=True)
[['I', 219], ['A', 22], ['P', 14], ['V', 13], ['G', 10], ...]
回答by Nikhil Kollanoor
Use itemgetter
用 itemgetter
from operator import itemgetter
a = [[1, 3, 5], [2, 511, 7], [17, 233, 1]]
a = sorted(a, key=itemgetter(1))
Output : [[1, 3, 5], [17, 233, 1], [2, 511, 7]]
输出：[[1, 3, 5], [17, 233, 1], [2, 511, 7]]
itemgettercan also be used to sort by multiple subarrays.
itemgetter也可用于按多个子数组排序。
回答by Manik
x= [[8, 9, 7],
[1, 2, 3],
[5, 4, 3],
[4, 5, 6]]
x.sort(cmp=lambda x,y: cmp(x[0],y[0]))
print x
回答by Nidhi Alipuria
Do this:
做这个：
Sort the multi-dimensional array in descending order on the basis of 2nd column:
在第 2 列的基础上按降序对多维数组进行排序：
list_name.sort(key=lambda x:x[1],reverse=True)
