python sorted 笔记

python sorted笔记

数据: data = [ { ‘name’:’foo’, ‘age’: 23, ‘job’: ‘banana’, }, { ‘name’:’bar’, ‘age’: 54, ‘job’: ‘watermelon’, }, { ‘name’:’xx’, ‘age’: 35, ‘job’: ‘apple’, }, ]

问题:

1. 按name排序
2. 按name, age,排序
3. 按name,age, job排序

解决方案使用 sorted key参数说明: 返回了一组比较序列. operator.itemgetter返回拿属性的值 例子: itemgetter(‘name’,’age’)(data[0]) -> [‘foo’, 2]

由此看来适合做sorted的key

1. sorted(data, key=itemgetter(‘name’)) -> [{‘age’: 54, ‘job’: ‘watermelon’, ‘name’: ‘bar’}, {‘age’: 23, ‘job’: ‘banana’, ‘name’: ‘foo’}, {‘age’: 35, ‘job’: ‘apple’, ‘name’: ‘xx’}]

2. sorted(data, key=itemgetter(‘name’, ‘age’)) -> [{‘age’: 54, ‘job’: ‘watermelon’, ‘name’: ‘bar’}, {‘age’: 23, ‘job’: ‘banana’, ‘name’: ‘foo’}, {‘age’: 35, ‘job’: ‘apple’, ‘name’: ‘xx’}]

3. sorted(data, key=itemgetter(‘name’, ‘age’, ‘job’)) -> [{‘age’: 54, ‘job’: ‘watermelon’, ‘name’: ‘bar’}, {‘age’: 23, ‘job’: ‘banana’, ‘name’: ‘foo’}, {‘age’: 35, ‘job’: ‘apple’, ‘name’: ‘xx’}]

注意 要明确看出结果的区别,则要数据要改进.