# Need help about how to write a filter with python client v4

**URL:** <https://forum.weaviate.io/t/need-help-about-how-to-write-a-filter-with-python-client-v4/1317>\
**Category:** Support\
**Created:** [January 29, 2024, 2:40am UTC](https://forum.weaviate.io/t/need-help-about-how-to-write-a-filter-with-python-client-v4/1317 "2024-01-29T02:40:57Z")\
**Posts on this page:** 9\
**Page:** 1

<div class="post-metadata">

**Author:** ![shadowlin](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.weaviate.io/shadowlin/32/800_2.png) [@shadowlin](https://forum.weaviate.io/u/shadowlin)\
**Post date:** [January 29, 2024, 2:40am UTC](https://forum.weaviate.io/t/need-help-about-how-to-write-a-filter-with-python-client-v4/1317/1 "2024-01-29T02:40:57Z")

</div>

let’s say I have objects as below:  
A1{  
has\_b:[B1,B2] # references  
}

A2{  
has\_b:[B3,B4] # references  
}

B1{  
field1:1  
field2:2  
}

B2{  
field1:3  
field2:4  
}

B3{  
field1:1  
field2:3  
}

B4{  
field1:2  
field2:4  
}

if I use I filter like this on collection A  
Filter.by\_ref(“has\_b”).by\_property(“field1”).equal(1) & Filter.by\_ref(“has\_b”).by\_property(“field2”).equal(2)

with current filter I can get both A1 and A1, because the filter find B3 has field1=1 and B4 has field=2 so also find A2 which I don’t want.

I actually want to find only A1 because I want to find the A object which have a B object refernece with field1=1 and field2=2 in the same B object which should only be A1 with B1 reference.

Is this possible? how to write the filter or graphql? Thanks

---

<div class="post-metadata">

**Author:** ![Dirk](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.weaviate.io/dirk/32/46_2.png) [@Dirk](https://forum.weaviate.io/u/Dirk)\
**Post date:** [January 29, 2024, 4:57am UTC](https://forum.weaviate.io/t/need-help-about-how-to-write-a-filter-with-python-client-v4/1317/2 "2024-01-29T04:57:12Z")

</div>

HI, I just tested this and it works as expected:

```auto
import weaviate
from weaviate.collections.classes.config import Property, DataType, ReferenceProperty
from weaviate.collections.classes.filters import Filter

client = weaviate.connect_to_local()
client.collections.delete(["a", "b"])
b = client.collections.create(
    "a",
    properties=[
        Property(name="field1", data_type=DataType.INT),
        Property(name="field2", data_type=DataType.INT),
    ],
)
a = client.collections.create(
    name="b", references=[ReferenceProperty(name="has_b", target_collection=b.name)]
)
b1 = b.data.insert(properties={"field1": 1, "field2": 2})
b2 = b.data.insert(properties={"field1": 3, "field2": 4})
b3 = b.data.insert(properties={"field1": 1, "field2": 3})
b4 = b.data.insert(properties={"field1": 2, "field2": 4})

a1 = a.data.insert({}, references={"has_b": [b1, b2]})
a2 = a.data.insert({}, references={"has_b": [b3, b4]})

objects = a.query.fetch_objects(
    filters=Filter.by_ref("has_b").by_property("field1").equal(1)
    & Filter.by_ref("has_b").by_property("field2").equal(2),
).objects
assert len(objects) == 1
assert objects[0].uuid == a1

```

(Note that if you do a code-block if you use ``` which makes things easier to read)

---

<div class="post-metadata">

**Author:** ![shadowlin](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.weaviate.io/shadowlin/32/800_2.png) [@shadowlin](https://forum.weaviate.io/u/shadowlin)\
**Post date:** [January 29, 2024, 9:46am UTC](https://forum.weaviate.io/t/need-help-about-how-to-write-a-filter-with-python-client-v4/1317/3 "2024-01-29T09:46:34Z")

</div>

@Dirk  
Thank you for the quick reply.  
I will try your code as soon as possible.  
I just want to make sure if I understand right.  
So filter like this:

```auto
filters=Filter.by_ref("has_b").by_property("field1").equal(1)
    & Filter.by_ref("has_b").by_property("field2").equal(2)

```

means to find the A object has reference of B object with filed1=1 and field2=2 in one B object right?  
My actual case is a filter like this but I think nested ref shouldn’t effect this.

```auto
Filter.by_ref("belong_to_file_data").by_ref("belong_to_file").by_property("auth_buss_id").equal(file_auth.auth_buss_id) &
Filter.by_ref("belong_to_file_data").by_ref("belong_to_file").by_property("auth_type").equal(file_auth.auth_type) &
Filter.by_ref("belong_to_file_data").by_ref("belong_to_file").by_property("auth_level").less_or_equal(file_auth.auth_level)

```

I want to filter by the file object with “auth\_buss\_id”,“auth\_type”,“auth\_level” meet condition in the same file.

But I got some result with none of the file can match the all of the three condition at the same time but only partial of it.I will do more test.

---

<div class="post-metadata">

**Author:** ![shadowlin](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.weaviate.io/shadowlin/32/800_2.png) [@shadowlin](https://forum.weaviate.io/u/shadowlin)\
**Post date:** [January 29, 2024, 10:59am UTC](https://forum.weaviate.io/t/need-help-about-how-to-write-a-filter-with-python-client-v4/1317/4 "2024-01-29T10:59:00Z")

</div>

I tried your code.  
Is there a small mistake in your code?

```auto
b = client.collections.create(
    "a",
    properties=[
        Property(name="field1", data_type=DataType.INT),
        Property(name="field2", data_type=DataType.INT),
    ],
)

```

should it be like this?

```auto
b = client.collections.create(
    "b",
    properties=[
        Property(name="field1", data_type=DataType.INT),
        Property(name="field2", data_type=DataType.INT),
    ],
)

```

your example did work as expect but if I change the filter to like this:

```auto
client.collections.delete(["a", "b",])
b = client.collections.create(
    "b",
    properties=[
        Property(name="field1", data_type=DataType.INT),
        Property(name="field2", data_type=DataType.INT),
    ],
)
a = client.collections.create(
    name="a", references=[ReferenceProperty(name="has_b", target_collection=b.name)]
)

b1 = b.data.insert(properties={"field1": 1, "field2": 2})
b2 = b.data.insert(properties={"field1": 3, "field2": 4})
b3 = b.data.insert(properties={"field1": 1, "field2": 3})
b4 = b.data.insert(properties={"field1": 2, "field2": 4})

a1 = a.data.insert({}, references={"has_b": [b1, b2]})
a2 = a.data.insert({}, references={"has_b": [b3, b4]})

objects = a.query.fetch_objects(
    filters=Filter.by_ref("has_b").by_property("field1").equal(1)
            & Filter.by_ref("has_b").by_property("field2").equal(4),
).objects

print(objects)
print(len(objects))

```

there should be no b object with field1==1 and field2==4, but the result is like:

```auto
[Object(uuid=_WeaviateUUIDInt('795f9ef0-76c6-4e8e-9113-91933f442ddf'), metadata=MetadataReturn(creation_time=None, last_update_time=None, distance=None, certainty=None, score=None, explain_score=None, is_consistent=None, rerank_score=None), properties={}, references=None, vector=None, collection='A'), Object(uuid=_WeaviateUUIDInt('864c1bce-5354-4fd3-b7ea-0627f74ae5cb'), metadata=MetadataReturn(creation_time=None, last_update_time=None, distance=None, certainty=None, score=None, explain_score=None, is_consistent=None, rerank_score=None), properties={}, references=None, vector=None, collection='A')]
2

```

---

<div class="post-metadata">

**Author:** ![Dirk](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.weaviate.io/dirk/32/46_2.png) [@Dirk](https://forum.weaviate.io/u/Dirk)\
**Post date:** [January 29, 2024, 12:27pm UTC](https://forum.weaviate.io/t/need-help-about-how-to-write-a-filter-with-python-client-v4/1317/5 "2024-01-29T12:27:07Z")

</div>

That seems to be a bug - I’ll take a look (note I posted this in your other thread by accident first)

---

<div class="post-metadata">

**Author:** ![shadowlin](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.weaviate.io/shadowlin/32/800_2.png) [@shadowlin](https://forum.weaviate.io/u/shadowlin)\
**Post date:** [January 29, 2024, 2:11pm UTC](https://forum.weaviate.io/t/need-help-about-how-to-write-a-filter-with-python-client-v4/1317/6 "2024-01-29T14:11:20Z")

</div>

please let me know if there is any update.Thanks

---

<div class="post-metadata">

**Author:** ![Dirk](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.weaviate.io/dirk/32/46_2.png) [@Dirk](https://forum.weaviate.io/u/Dirk)\
**Post date:** [January 30, 2024, 3:09am UTC](https://forum.weaviate.io/t/need-help-about-how-to-write-a-filter-with-python-client-v4/1317/7 "2024-01-30T03:09:41Z")

</div>

I had a look and it seems to be a general problem and not GRPC/client related (so a GQL query gives the same result)

This is outside of my are of expertise and I don’t have time to dig onto that, could you create a bugreport at [Issues · weaviate/weaviate · GitHub](https://github.com/weaviate/weaviate/issues)?

---

<div class="post-metadata">

**Author:** ![shadowlin](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.weaviate.io/shadowlin/32/800_2.png) [@shadowlin](https://forum.weaviate.io/u/shadowlin)\
**Post date:** [January 30, 2024, 4:02am UTC](https://forum.weaviate.io/t/need-help-about-how-to-write-a-filter-with-python-client-v4/1317/8 "2024-01-30T04:02:05Z")

</div>

Ok. Thank you.  
Just want to make sure this behavior is unexpected , right?  
I am not familiar with GQL so I am not sure if this is a bug or expected behavior .

---

<div class="post-metadata">

**Author:** ![Dirk](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.weaviate.io/dirk/32/46_2.png) [@Dirk](https://forum.weaviate.io/u/Dirk)\
**Post date:** [January 30, 2024, 4:23am UTC](https://forum.weaviate.io/t/need-help-about-how-to-write-a-filter-with-python-client-v4/1317/9 "2024-01-30T04:23:52Z")

</div>

I would lean towards bug/unexpected behaviour.

I mentioned GQL because I used it to test if the client does something wrong or if it is how weaviate handles that query