Python3写法

代码

# -*- coding: utf-8 -*-

# 需求：年龄倒序，姓名正序

from itertools import chain
from pypinyin import pinyin, Style


class Student:
    def __init__(self, name, age):
        self.name = name
        self.age = age


def to_pinyin(stu):
    lst = pinyin(stu.name, style=Style.TONE3)  # 例：[['zhang1'], ['san1']]
    print(lst)
    iterator = chain.from_iterable(lst)  # 迭代器
    iterator_for_print = chain.from_iterable(lst)  # 迭代器
    print(iterator_for_print)
    for item in iterator_for_print:
        print(item)

    # 写法一
    return ''.join(iterator)

    # 写法二
    # return ''.join(chain.from_iterable(pinyin(stu.name, style=Style.TONE3)))


studentList = [
    Student("张三", 25),
    Student("小红", 22),
    Student("王五", 25),
    Student("小张", 22),
    Student("李四", 25),
    Student("小明", 22)
]

# 写法一
# studentList.sort(key=lambda stu: pinyin(stu.name, style=Style.TONE3))

# 写法二
studentList.sort(key=lambda stu: to_pinyin(stu))
studentList.sort(key=lambda stu: stu.age, reverse=True)

print("排序结果：")
for student in studentList:
    print(str(student.age) + " " + student.name)

输出结果

Python2写法

代码

# -*- coding: utf-8 -*-

# 需求：年龄倒序，姓名正序

from itertools import chain
from pypinyin import pinyin, Style


class Student:
    def __init__(self, name, age):
        self.name = name
        self.age = age


def to_pinyin(stu):
    lst = pinyin(stu.name.decode("utf-8"), style=Style.TONE3)  # 例：[['zhang1'], ['san1']]
    print(lst)
    iterator = chain.from_iterable(lst)  # 迭代器
    iterator_for_print = chain.from_iterable(lst)  # 迭代器
    print(iterator_for_print)
    for item in iterator_for_print:
        print(item)

    # 写法一
    return ''.join(iterator)

    # 写法二
    # return ''.join(chain.from_iterable(pinyin(stu.name.decode("utf-8"), style=Style.TONE3)))


studentList = [
    Student("张三", 25),
    Student("小红", 22),
    Student("王五", 25),
    Student("小张", 22),
    Student("李四", 25),
    Student("小明", 22)
]

# 写法一
# studentList.sort(key=lambda stu: pinyin(stu.name.decode("utf-8"), style=Style.TONE3))

# 写法二
studentList.sort(key=lambda stu: to_pinyin(stu))
studentList.sort(key=lambda stu: stu.age, reverse=True)

print("排序结果：")
for student in studentList:
    print(str(student.age) + " " + student.name)

输出结果

C#的示例

代码

List<Student> list = new List<Student>()
{
    new Student("张三", 25),
    new Student("小红", 22),
    new Student("王五", 25),
    new Student("小张", 22),
    new Student("李四", 25),
    new Student("小明", 22)
};

//方法一，虽然写法繁琐，但思路清晰
list.Sort((a, b) =>
{
    if (a.Age != b.Age)
    {
        return b.Age - a.Age;
    }
    else
    {
        return string.Compare(a.Name, b.Name);
    }
});

//方法二，简捷清晰明了
//list = list.OrderByDescending(a => a.Age).ThenBy(a => a.Name).ToList();

foreach (var item in list)
{
    Console.WriteLine(item.Age + " " + item.Name);
}

Console.Read();

class Student
{
    public string Name { get; set; }

    public int Age { get; set; }

    public Student(string name, int age)
    {
        Name = name;
        Age = age;
    }
}

输出结果

对比C#，Python的坑

1. Python默认的中文排序得不到预期的结果，需要引用pypinyin库解决，相当麻烦，要看懂这个代码，需要了解迭代器
2. Python2的pypinyin库只支持unicode编码的字符串，必须通过decode转码，如果不转码，则抛出错误：must be unicode string or [unicode, ...] list
3. Python没有大括号，无法直接在lambda表达式中写方法，方法必须