列表里面嵌套字典，按照字典里的键值排序

举例

ls = [{'a': 100}, {'a': 20}, {'a': 35}, {'a': 54}, {'a': 66}]

排序

ls = sorted(ls, key=lambda x: x['a'])
print(ls)
ls = sorted(ls, key=lambda x: x['a'], reverse=True)
print(ls)

结果

[{'a': 20}, {'a': 35}, {'a': 54}, {'a': 66}, {'a': 100}]
[{'a': 100}, {'a': 66}, {'a': 54}, {'a': 35}, {'a': 20}]