Python 使用sorted（）按每个元组的第一个值对元组进行排序

我需要按每个元组的第一个值对元组列表进行排序。我有密码：

import pandas as pd
import numpy as np

a= np.array([7.33442355e-02, 0.00000000e+00, 6.29090705e-02, 4.11437985e-02, 1.46726854e-02,
       1.41064835e-02, 1.48742809e-02, 1.42575993e-02, 3.66158981e-01,
       5.64191792e-02, 1.08792957e-01, 5.33510773e-02, 1.03114883e-02,
       1.64780994e-01, 6.02803867e-05, 1.96041560e-03, 2.85647464e-03])


b= ['longitude',
    'some_var',
    'latitude',
    'housing_median_age',
    'total_rooms',
    'total_bedrooms',
    'population',
    'households',
    'median_income',
    'rooms_per_hhold',
    'pop_per_hhold',
    'bedrooms_per_room',
    '<1H OCEAN',
    'INLAND',
    'ISLAND',
    'NEAR BAY',
    'NEAR OCEAN']

x=sorted(zip(a, b), reverse=True)

我需要输出如下所示：

 [(0.0, 'some_var'),
 (6.02803867e-05, 'ISLAND'),
 (0.0019604156, 'NEAR BAY'),
 (0.00285647464, 'NEAR OCEAN'),
 (0.0103114883, '<1H OCEAN'),
 (0.0141064835, 'total_bedrooms'),
 (0.0142575993, 'households'),
 (0.0146726854, 'total_rooms'),
 (0.0148742809, 'population'),
 (0.0411437985, 'housing_median_age'),
 (0.0533510773, 'bedrooms_per_room'),
 (0.0564191792, 'rooms_per_hhold'),
 (0.0629090705, 'latitude'),
 (0.0733442355, 'longitude'),
 (0.108792957, 'pop_per_hhold'),
 (0.164780994, 'INLAND'),
 (0.366158981, 'median_income')]

[（0.0，'some_var'），
（6.02803867e-05，“岛”），
（0.0019604156，'近海湾'），
（0.00285647464，“海洋附近”），
（0.0103114883，“使用lambda表达式：

lst =  [(0.366158981, 'median_income'),
 (0.164780994, 'INLAND'),
 (0.108792957, 'pop_per_hhold'),
 (0.0733442355, 'longitude'),
 (0.0629090705, 'latitude'),
 (0.0564191792, 'rooms_per_hhold'),
 (0.0533510773, 'bedrooms_per_room'),
 (0.0411437985, 'housing_median_age'),
 (0.0148742809, 'population'),
 (0.0146726854, 'total_rooms'),
 (0.0142575993, 'households'),
 (0.0141064835, 'total_bedrooms'),
 (0.0103114883, '<1H OCEAN'),
 (0.00285647464, 'NEAR OCEAN'),
 (0.0019604156, 'NEAR BAY'),
 (6.02803867e-05, 'ISLAND'),
 (0.0, 'some_var')]

lst = sorted(lst, key=lambda x: x[0])
print(lst)

这将产生

[(0.366158981, 'median_income'), (0.164780994, 'INLAND'), (0.108792957, 'pop_per_hhold'), (0.0733442355, 'longitude'), (0.0629090705, 'latitude'), (0.0564191792, 'rooms_per_hhold'), (0.0533510773, 'bedrooms_per_room'), (0.0411437985, 'housing_median_age'), (0.0148742809, 'population'), (0.0146726854, 'total_rooms'), (0.0142575993, 'households'), (0.0141064835, 'total_bedrooms'), (0.0103114883, '<1H OCEAN'), (0.00285647464, 'NEAR OCEAN'), (0.0019604156, 'NEAR BAY'), (6.02803867e-05, 'ISLAND'), (0.0, 'some_var')]

使用lambda表达式：

lst =  [(0.366158981, 'median_income'),
 (0.164780994, 'INLAND'),
 (0.108792957, 'pop_per_hhold'),
 (0.0733442355, 'longitude'),
 (0.0629090705, 'latitude'),
 (0.0564191792, 'rooms_per_hhold'),
 (0.0533510773, 'bedrooms_per_room'),
 (0.0411437985, 'housing_median_age'),
 (0.0148742809, 'population'),
 (0.0146726854, 'total_rooms'),
 (0.0142575993, 'households'),
 (0.0141064835, 'total_bedrooms'),
 (0.0103114883, '<1H OCEAN'),
 (0.00285647464, 'NEAR OCEAN'),
 (0.0019604156, 'NEAR BAY'),
 (6.02803867e-05, 'ISLAND'),
 (0.0, 'some_var')]

lst = sorted(lst, key=lambda x: x[0])
print(lst)

这将产生

[(0.366158981, 'median_income'), (0.164780994, 'INLAND'), (0.108792957, 'pop_per_hhold'), (0.0733442355, 'longitude'), (0.0629090705, 'latitude'), (0.0564191792, 'rooms_per_hhold'), (0.0533510773, 'bedrooms_per_room'), (0.0411437985, 'housing_median_age'), (0.0148742809, 'population'), (0.0146726854, 'total_rooms'), (0.0142575993, 'households'), (0.0141064835, 'total_bedrooms'), (0.0103114883, '<1H OCEAN'), (0.00285647464, 'NEAR OCEAN'), (0.0019604156, 'NEAR BAY'), (6.02803867e-05, 'ISLAND'), (0.0, 'some_var')]

为什么
6.02803867e-05
应该排在第一位？因为指数，它是一个非常小的值，而不是最高的值。
import操作符
和
lst.sort（key=operator.itemgetter（0））
@Barmar你说得对。我怎么会错过它是用科学记数法写的呢？非常感谢你的评论！@GrijeshChauhan，这不是必须的。元组是按字典顺序排列的，所以它默认按第一个元素排序。@Barmar是的，正确。谢谢你提醒我。
6.02803867e-05
为什么要排在第一位？因为指数，它是一个非常小的值，不是最高值。
import操作符
和
lst.sort（key=operator.itemgetter（0））
@Barmar你说得对。我怎么会错过它是用科学记数法写的呢？非常感谢你的评论！@GrijeshChauhan，这不是必需的。元组是按字典顺序排列的，所以它默认按第一个元素排序。@Barmar是的，正确。谢谢你提醒我。你不需要lambda表达式。元组是按字母顺序进行比较的以图像方式，它会自动首先比较第一个元素。您不需要lambda表达式。元组是按字典进行比较的，因此它会自动首先比较第一个元素。
[(0.366158981, 'median_income'), (0.164780994, 'INLAND'), (0.108792957, 'pop_per_hhold'), (0.0733442355, 'longitude'), (0.0629090705, 'latitude'), (0.0564191792, 'rooms_per_hhold'), (0.0533510773, 'bedrooms_per_room'), (0.0411437985, 'housing_median_age'), (0.0148742809, 'population'), (0.0146726854, 'total_rooms'), (0.0142575993, 'households'), (0.0141064835, 'total_bedrooms'), (0.0103114883, '<1H OCEAN'), (0.00285647464, 'NEAR OCEAN'), (0.0019604156, 'NEAR BAY'), (6.02803867e-05, 'ISLAND'), (0.0, 'some_var')]

lst1 = sorted(lst, key=lambda x: x[0])
lst2 = sorted(lst)
assert lst1 == lst2