提问人:David Gard 提问时间:4/6/2023 更新时间:4/6/2023 访问量:43
比较列表中的对象,以识别具有某些相同键/值对的对象和没有键/值对的对象
Compare objects in a list to identify those with certain identical key/value pairs and those without
问:
使用 Python,如何在列表中找到共享某些键/值对的对象,然后创建两个单独的列表 - 一个用于共享这些特定键/值对的对象,另一个用于不共享这些特定键/值对的对象?
例如,以以下简单列表为例 -
[
{
"id": "111",
"host": "aaa",
"path": "/b/c/d"
},
{
"id": "222",
"host": "bbb",
"path": "/x/y/z"
},
{
"id": "333",
"host": "aaa",
"path": "/b/c/d"
},
{
"id": "444",
"host": "aaa",
"path": "/b/c/d"
}
]
我想最后列出两个清单——
具有 duplicate 和 .
host
path
[ { "host": "aaa", "path": "/b/c/d" "ids": [ "111", "333", "444", } ]
没有重复项和 .
host
path
[ { "id": "222", "host": "bbb", "path": "/x/y/z" } ]
到目前为止,我最好的尝试产生了两个列表,但是原始列表中的所有对象都被添加到 ,无论它们是否真的是重复的。dups_list
请注意,我尝试在第二个语句中使用 of,但这产生了完全相同的结果。deepcopy
main_list
for
>>> import jsonpickle
>>> main_list = list((dict(Id="111",host="aaa",path="/b/c/d"),dict(Id="222",host="bbb",path="/x/y/z"),dict(Id="333",host="aaa",path="/b/c/d"),dict(Id="444",host="aaa",path="/b/c/d")))
>>> dups_list = list()
>>> non_dups_list = list()
>>> for o in main_list:
... is_duplicate = False
... for o2 in main_list:
... if o2['host'] == o['host'] and o2['path'] == o['path']:
... is_duplicate = True
... break
... if is_duplicate:
... dups_list.append(o)
... else:
... non_dups_list.append(o)
...
>>> print(jsonpickle.encode(non_dups_list, indent=4))
[]
>>> print(jsonpickle.encode(dups_list, indent=4))
[
{
"Id": "111",
"host": "aaa",
"path": "/b/c/d"
},
{
"Id": "222",
"host": "bbb",
"path": "/x/y/z"
},
{
"Id": "333",
"host": "aaa",
"path": "/b/c/d"
},
{
"Id": "444",
"host": "aaa",
"path": "/b/c/d"
}
]
答:
1赞
JLamHK
4/6/2023
#1
我建议使用 itertools。
from itertools import groupby
def get_key(d):
# Define a custom key function to group by multiple keys
return d['host'], d['path']
data = [...your data here]
grouped_data = []
for k, g in groupby(sorted(data, key=get_key), key=get_key):
grouped_data.append({'host': k[0], 'path': k[1], 'ids': [i['id'] for i in list(g)]})
评论
0赞
David Gard
4/6/2023
Thanks for your reply. While this works for the duplicates, it also includes the duplicates, all non-duplicates are also included in the list, rather than being in a separate list. Additionally, other keys are excluded from both results (not included in my examples, will add a note to say it exists), and the non-duplicates are transformed where they should not be (see my example output). But thanks for introducing my to .itertools
1赞
Timeless
4/6/2023
#2
I would use defaultdict
with dict/listcomps :
from collections import defaultdict
g = defaultdict(list)
for obj in list_objs:
g[(obj["host"], obj["path"])].append(obj["id"])
dups = [{"host": k[0], "path": k[1], "ids": v} for k, v in g.items() if len(v) > 1]
uniqs = [obj for obj in list_objs if (obj["host"], obj["path"])
not in [k for k, v in g.items() if len(v) > 1]]
#12.2 µs ± 316 ns per loop (mean ± std. dev. of 7 runs, 100,000 loops each)
Output :
>>> print(dups)
#[{'host': 'aaa', 'path': '/b/c/d', 'ids': ['111', '333', '444']}]
>>> print(uniqs)
#[{'id': '222', 'host': 'bbb', 'path': '/x/y/z'}]
评论
1赞
Timeless
4/6/2023
NB : is the variable holding the list of objects/dictionnaries.list_objs
1赞
David Gard
4/6/2023
Perfect, and so much simpler than what I was trying. Thanks very much.
评论