Python根据文件数据的两个字段排序

Question

我尝试使用同一问题中接受的解决方案中描述的方法对给定 here 的数据进行排序。我制作了列表列表，而不是集合列表，并尝试使用 sorted 方法进行两次排序。但它没有用。我想要与上面链接中给出的相同的输出。这是我的输出:

[['k3', '9.2603346875', '0.4639390435'],
['K1', '4.1458078125', '0.5129700421'],
['k2', '9.5360690625', '0.5481493305'],
 ['k7', '9.8022878125', '0.562983695'],
 ['k2', '6.319044375', '0.6469451082'],
 ['k5', '7.2702040625', '0.6632701035'],
 ['K1', '8.6394253125', '0.6690271589'],
 ['K1', '8.025495625', '0.7561548244'],
 ['k8', '5.44912125', '0.8532092538'],
 ['k6', '7.73398625', '1.017231759'],
 ['K1', '6.66228125', '1.0444456163'],
 ['k4', '10.6868384375', '1.1287761798'],
 ['k9', '7.5859665625', '1.276779643'],
 ['K1', '6.48153375', '1.4176140292']]

这是我的代码:

path = "C:\\Chandresh_WORK\\data\\"
inpfile = 'demo1.txt'
mylist=[]
from operator import itemgetter
with open(path+inpfile,'r') as fid:
    for line in fid:      
        myset = list(line.split())
        mylist.append(myset)

mylist
s=sorted(mylist,key=itemgetter(0))     
sorted(s,key=itemgetter(2))

Answer 1

您需要将字符串转换为数字类型以避免字典排序，然后反转第二个排序标准的顺序以使其降序:

s = sorted(mylist,key=lambda x: (x[0], -float(x[2]))) 
#                                      ^ invert sort order

---

[['K1', '6.48153375', '1.4176140292'],
 ['K1', '6.66228125', '1.0444456163'],
 ['K1', '8.025495625', '0.7561548244'],
 ['K1', '8.6394253125', '0.6690271589'],
 ['K1', '4.1458078125', '0.5129700421'],
 ['k2', '6.319044375', '0.6469451082'],
 ['k2', '9.5360690625', '0.5481493305'],
 ['k3', '9.2603346875', '0.4639390435'],
 ['k4', '10.6868384375', '1.1287761798'],
 ['k5', '7.2702040625', '0.6632701035'],
 ['k6', '7.73398625', '1.017231759'],
 ['k7', '9.8022878125', '0.562983695'],
 ['k8', '5.44912125', '0.8532092538'],
 ['k9', '7.5859665625', '1.276779643']]