从 pydantic 对象列表中删除重复项

Question

我试图从 pydantic 对象列表中删除重复项，但遇到了一个我无法解决的问题。唯一的工作方式很慢。

有没有比我的方法更快的删除重复项的方法？

代码：

Pydantic 模型 (a.py)

from pydantic import BaseModel


class Photo(BaseModel):
    title: str
    url: str

主文件(b.py)

from collections import OrderedDict
from a import Photo

#  3 objects, 2 duplicates
a_obj = {
    'title': 'SOME TITLE v1',
    'url': 'http://some.url'
}
b_obj = {
    'title': 'SOME TITLE v2',
    'url': 'http://different.url'
}
c_obj = {
    'title': 'SOME TITLE v1',
    'url': 'http://some.url'
}

#  Creating list of pydantic objects
pd_obj_list = list()
pd_obj_list += [Photo(**a_obj)]
pd_obj_list += [Photo(**b_obj)]
pd_obj_list += [Photo(**c_obj)]

#  My Attempts to Remove Duplicates

#  Using OrderedDict.fromkeys
final_list_0 = list(OrderedDict.fromkeys(pd_obj_list))
#  returns TypeError: unhashable type: 'Photo'

#  Using Set
final_list_1 = list(set(pd_obj_list))
#  returns TypeError: unhashable type: 'Photo'

#  Using enumerate
final_list_2 = [i for n, i in enumerate(pd_obj_list) if i not in pd_obj_list[:n]]
#  It works but too slow when I have ~10k objects in the list

Answer 1

使用：

pd_obj_list = [Photo(**a_obj), Photo(**b_obj), Photo(**c_obj)]
final_list_0 = list(OrderedDict(((photo.title, photo.url), photo) for photo in pd_obj_list).values())
print(final_list_0)

输出

[Photo(title='SOME TITLE v1', url='http://some.url'), Photo(title='SOME TITLE v2', url='http://different.url')]

如果照片 不可变 你可以定义 __hash__ 如下：

from collections import OrderedDict

from pydantic import BaseModel


class Photo(BaseModel):
    title: str
    url: str

    def __hash__(self):
        return hash((self.title, self.url))


#  3 objects, 2 duplicates
a_obj = {
    'title': 'SOME TITLE v1',
    'url': 'http://some.url'
}
b_obj = {
    'title': 'SOME TITLE v2',
    'url': 'http://different.url'
}
c_obj = {
    'title': 'SOME TITLE v1',
    'url': 'http://some.url'
}

pd_obj_list = [Photo(**a_obj), Photo(**b_obj), Photo(**c_obj)]
final_list_0 = list(OrderedDict.fromkeys(pd_obj_list))
print(final_list_0)

输出

[Photo(title='SOME TITLE v1', url='http://some.url'), Photo(title='SOME TITLE v2', url='http://different.url')]

从 pydantic 对象列表中删除重复项

Removing duplicates from the list of pydantic objects

python

list

performance

duplicates

pydantic