檢查python列表中是否有兩個（或多個）具有相同屬性值的自定義對象

Question

我有這個“問題”：

我有一個包含自定義對象的Python 列表，例如list = [Object1, Object2, Object3, ..., ObjectN] ，我想檢查是否存在一些具有相同屬性值的元素。

因此，如果所有對象具有不同的屬性值，則函數checkDuplicateAttr(list)應返回 None，否則返回重復屬性對象的列表。

例子：

Foo = newObject(value=1, name="foo")
Bar = newObject(value=4, name="bar")
Car = newObject(value=1, name="car")
list = [Foo, Bar, Car]

if x = checkDuplicateAttr(list) is None:
    print("There are no duplicate attribute values")
else:
    print("There are duplicate value elements", x)

對於我的示例，輸出應該是：

OUTPUT:
There are duplicate Value elements: [Foo, Car]

Answer 1

請檢查以下代碼是否對您有幫助：

from typing import List
from itertools import groupby


class MyCustomObj:
    def __init__(self, value, name):
        self.name = name
        self.value = value

    def __repr__(self):
        return self.name


def checkDuplicateAttr(objects: List[MyCustomObj]):
    obj_group_by_value = [
        list(g[1])
        for g in groupby(
            sorted(objects, key=lambda obj: obj.value), lambda obj: obj.value
        )
    ]
    return list(filter(lambda objs: len(objs) > 1, obj_group_by_value)) or None


Foo = MyCustomObj(value=1, name="foo")
Bar = MyCustomObj(value=4, name="bar")
Car = MyCustomObj(value=1, name="car")

x = checkDuplicateAttr([Foo, Bar, Car])
if x is None:
    print("There are no duplicate attribute values")
else:
    print(
        "There are duplicate value elements {}".format(
            x[0] if len(x) == 1 else x
        )
    )