详解Python3中的自定义排序

# 基础示例
numbers = [5, 2, 9, 1, 5, 6]
sorted_numbers = sorted(numbers)
print(sorted_numbers)  # 输出: [1, 2, 5, 5, 6, 9]
#使用sort()方法：
 
python
numbers = [5, 2, 9, 1, 5, 6]
numbers.sort()
print(numbers)  # 输出: [1, 2, 5, 5, 6, 9]

words = ["apple", "banana", "cherry", "date"]
sorted_words = sorted(words, key=len)
print(sorted_words)  # 输出: ['date', 'apple', 'banana', 'cherry']

pairs = [(1, 3), (4, 1), (2, 5), (3, 2)]
sorted_pairs = sorted(pairs, key=lambda x: x[1])
print(sorted_pairs)  # 输出: [(4, 1), (3, 2), (1, 3), (2, 5)]

numbers = [5, 2, 9, 1, 5, 6]
sorted_numbers_desc = sorted(numbers, reverse=True)
print(sorted_numbers_desc)  # 输出: [9, 6, 5, 5, 2, 1]

numbers = [5, 2, 9, 1, 5, 6]
numbers.sort(reverse=True)
print(numbers)  # 输出: [9, 6, 5, 5, 2, 1]

people = [('Alice', 25), ('Bob', 30), ('Alice', 22)]
sorted_people = sorted(people, key=lambda x: (x[0], x[1]))
print(sorted_people)  # 输出: [('Alice', 22), ('Alice', 25), ('Bob', 30)]

people = {"Alice": 30, "Bob": 25, "Charlie": 35}
sorted_people = sorted(people.items(), key=lambda x: x[1])
print(sorted_people)  # 输出: [('Bob', 25), ('Alice', 30), ('Charlie', 35)]

class Person:
    def __init__(self, name, age):
        self.name = name
        self.age = age
    
    def __repr__(self):
        return f"Person{name=self.name, age=self.age}"
 
# 创建Person对象
people = [Person("Alice", 30), Person("Bob", 25), Person("Charlie", 35)]
# 按年龄排序
sorted_people = sorted(people, key=lambda person: person.age)
for person in sorted_people:
    print(person)
# 输出: Person{name='Bob', age=25}, Person{name='Alice', age=30}, Person{name='Charlie', age=35}

from functools import cmp_to_key
 
# 自定义比较函数
def compare(a, b):
    if a % 2 == b % 2:
        return a - b  # 相同类型（奇偶性）按大小排序
    return -1 if a % 2 == 0 else 1  # 偶数优先
 
numbers = [1, 2, 3, 4, 5, 6, 7, 8]
sorted_numbers = sorted(numbers, key=cmp_to_key(compare))
print(sorted_numbers)  # 输出: [2, 4, 6, 8, 1, 3, 5, 7]

tickets = [
    {'车次': 'G1', '历时': "1:23", '二等座': "有"},
    {'车次': 'G2', '历时': "1:00", '二等座': "有"},
    {'车次': 'G3', '历时': "0:23", '二等座': "13"},
    {'车次': 'G4', '历时': "1:55", '二等座': "44"},
    {'车次': 'G5', '历时': "0:21", '二等座': "13"},
    {'车次': 'G6', '历时': "1:55", '二等座': "44"}
]
 
# 定义比较函数
def cmp_seat(t1, t2):
    if t1["二等座"] == "有":
        if t2["二等座"] == "有":
            return 0
        else:
            return -1
    else:
        if t2["二等座"] == "有":
            return 1
        else:
            return int(t2["二等座"]) - int(t1["二等座"])
 
def cmp_time(t1, t2):
    hs1 = t1["历时"].split(":")
    hs2 = t2["历时"].split(":")
    tm1 = int(hs1[0]) * 60 + int(hs1[1])
    tm2 = int(hs2[0]) * 60 + int(hs2[1])
    return tm1 - tm2
 
def cmp(t1, t2):
    if cmp_seat(t1, t2) != 0:
        return cmp_seat(t1, t2)
    else:
        return cmp_time(t1, t2)
 
# 使用cmp_to_key进行排序
tickets.sort(key=cmp_to_key(cmp))
for ticket in tickets:
    print(ticket)