filter_docs fail to apply `and` when both parts of query refer to same field about docarray

[JoanFM]

This can be easily reproduced with this:

from docarray import BaseDoc, DocList
from typing import Optional
from docarray.utils.filter import filter_docs


class ImageDoc(BaseDoc):
    test_index: Optional[int]


da = DocList[BaseDoc]([ImageDoc(test_index=1), ImageDoc(test_index=3), ImageDoc(test_index=9)])

query = {
    '$and': {
        'test_index': {'$neq': 3},
        'test_index': {'$neq': 9}
    }
}
da2 = filter_docs(da, query=query)

print(f'da2 {da2}')
for d in da2:
    print(f'{d.test_index}')

[JoanFM]

This is not a bug, this is normal, what needs to be done is to change the query to:

query = {
 'test_index': {'$nin': [3, 9]},
}
da2 = filter_docs(da, query=query)

print(f'da2 {da2}')
for d in da2:
    print(f'{d.test_index}')