排序numpy数组时输出错误

Question

我写了一个python代码，该代码按升序对第二列中的多维numpy数组进行排序

import numpy as np
xt = [['S_P' , '9'  ,'42'],['S_SB', '9', '30'],['C_G' ,'14', '17'],['T_G', '12' ,'25'],['C_O' ,'14' ,'34'],['C_P' ,'14', '39'],['C_SB' ,'14' ,'20'],['T_O','12' ,'39']]

xb =  sorted(xt , key=lambda x: x[1])
xb = np.array(xb)
print xb

输出是

[['T_G' '12' '25'] 
 ['T_O' '12' '39'] 
 ['C_G' '14' '17']  
 ['C_O' '14' '34'] 
 ['C_P' '14' '39'] 
 ['C_SB' '14' '20'] 
 ['S_P' '9' '42'] 
 ['S_SB' '9' '30']]

我期望的结果是

>   [['S_P' '9' '42'] 
>      ['S_SB' '9' '30']
>      ['T_G' '12' '25'] 
>      ['T_O' '12' '39'] 
>      ['C_G' '14' '17']  
>      ['C_O' '14' '34'] 
>      ['C_P' '14' '39'] 
>      ['C_SB' '14' '20']]

我正在使用python 2.7

Answer 1

我认为您错过了int电话。 当前它正在对第一个值进行排序，就好像它们是字符串一样。 在这种情况下，“ 12”小于“ 9”。

xb =  sorted(xt , key=lambda x: int(x[1]))
xb = np.array(xb) 
print xb