Python 如何按对象的变量对对象进行分组？

我想知道是否有一种简单的方法可以通过变量将一些对象分组

我尝试过在对象之间循环，创建单独的集合，然后再次创建新对象，但我觉得我的方法太复杂了，有没有常见的简单方法

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

dogs = [Dog('Buddy', 3), Dog('Max', 3), Dog('Charlie', 5), 
    Dog('Cooper', 1), Dog('Jack', 3),Dog('Rocky', 4), Dog('Bear', 1), 
    Dog('Duke', 3), Dog('Ace', 5)]


 grouped_dogs = [(Dog('Buddy', 3), Dog('Max', 3), Dog('Duke', 3)), 
     (Dog('Charlie', 5)), (Dog('Cooper', 1), Dog('Bear', 1)), 
     (Dog('Rocky', 4))] # expected output

---

我希望它最终能像分组狗一样被年龄分组。

你可以使用

groupby

：

import itertools as it

groups = it.groupby(dogs, key=lambda x: x.age)
grouped_dogs = []

for _, items in groups:
    grouped_dogs.append([(x.name, x.age) for x in items])

---

您可以使用

键

变量对您的狗进行排序，然后使用itertools模块的功能：

from itertools import groupby

class Dog:
    def __init__(self, name, age):
        self.name = name
        self.age = age
    def __str__(self):
        return (self.name, self.age)

dogs = [Dog('Buddy', 3), Dog('Max', 3), Dog('Charlie', 5), 
    Dog('Cooper', 1), Dog('Jack', 3),Dog('Rocky', 4), Dog('Bear', 1), 
    Dog('Duke', 3), Dog('Ace', 5)]

sorted_dogs = sorted(dogs, key=lambda x: x.age)

print([(d.name, d.age) for d in sorted(dogs, key=lambda x: x.age)])

for u, v in groupby(sorted_dogs, key=lambda x: x.age):
    print(u, [(d.name, d.age) for d in v])

[('Cooper', 1), ('Bear', 1), ('Buddy', 3), ('Max', 3), ('Jack', 3), ('Duke', 3), ('Rocky', 4), ('Charlie', 5), ('Ace', 5)]


1 [('Cooper', 1), ('Bear', 1)]
3 [('Buddy', 3), ('Max', 3), ('Jack', 3), ('Duke', 3)]
4 [('Rocky', 4)]
5 [('Charlie', 5), ('Ace', 5)]