python

python 按字典value排序以及按list中字典的某个key的value排序

按照字典value排序

1
2
3
4
5
6
7
8
9
student_1={
    'a':2,
    'b':4,
    'c':6,
    'd':8
}

student_1_sort = sorted(student_1.iteritems(), key=lambda d: d[1], reverse=True)
print(student_1_sort)

输出：

1
[('d', 8), ('c', 6), ('b', 4), ('a', 2)]

按list中字典的某个key的value排序

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
student_2 = [
    {
        "no": 1,
        "score": 90
    },
    {
        "no": 2,
        "score": 90
    },
    {
        "no": 3,
        "score": 88
    },
    {
        "no": 4,
        "score": 92
    },
]

print("original: {0}".format(student_2))

单级排序，仅按照score排序

1
2
3
student_2_sort_1 = sorted(student_2, key=lambda e: e.__getitem__('score'))

print("sort by 1 key: ", student_2_sort_1)

多级排序,先按照score，再按照no排序

1
2
3
student_2_sort_2 = sorted(student_2, key=lambda e:(e.__getitem__('score'), e.__getitem__('no')))

print("sort by 2 keys: ", student_2_sort_2)

输出：

1
2
3
4
5
original: [{'score': 90, 'no': 1}, {'score': 90, 'no': 2}, {'score': 88, 'no': 3}, {'score': 92, 'no': 4}]

sort by 1 key:  [{'score': 88, 'no': 3}, {'score': 90, 'no': 1}, {'score': 90, 'no': 2}, {'score': 92, 'no': 4}]

sort by 2 keys:  [{'score': 88, 'no': 3}, {'score': 90, 'no': 1}, {'score': 90, 'no': 2}, {'score': 92, 'no': 4}]

降序排序使用：result_list = sorted(student_2, key=lambda e: e.__getitem__('score'), reverse=True)