langchain/tests/integration_tests/vectorstores/test_faiss.py
HenriZuber e0605b464b
feat: faiss filter from list (#6537)
### Feature

Using FAISS on a retrievalQA task, I found myself wanting to allow in
multiple sources. From what I understood, the filter feature takes in a
dict of form {key: value} which then will check in the metadata for the
exact value linked to that key.
I added some logic to be able to pass a list which will be checked
against instead of an exact value. Passing an exact value will also
work.

Here's an example of how I could then use it in my own project:

```
    pdfs_to_filter_in = ["file_A", "file_B"]
    filter_dict = {
        "source": [f"source_pdfs/{pdf_name}.pdf" for pdf_name in pdfs_to_filter_in]
    }
    retriever = db.as_retriever()
    retriever.search_kwargs = {"filter": filter_dict}
```

I added an integration test based on the other ones I found in
`tests/integration_tests/vectorstores/test_faiss.py` under
`test_faiss_with_metadatas_and_list_filter()`.

It doesn't feel like this is worthy of its own notebook or doc, but I'm
open to suggestions if needed.

Co-authored-by: Dev 2049 <dev.dev2049@gmail.com>
2023-06-21 10:49:01 -07:00

197 lines
7.6 KiB
Python

"""Test FAISS functionality."""
import datetime
import math
import tempfile
import pytest
from langchain.docstore.document import Document
from langchain.docstore.in_memory import InMemoryDocstore
from langchain.docstore.wikipedia import Wikipedia
from langchain.vectorstores.faiss import FAISS
from tests.integration_tests.vectorstores.fake_embeddings import FakeEmbeddings
def test_faiss() -> None:
"""Test end to end construction and search."""
texts = ["foo", "bar", "baz"]
docsearch = FAISS.from_texts(texts, FakeEmbeddings())
index_to_id = docsearch.index_to_docstore_id
expected_docstore = InMemoryDocstore(
{
index_to_id[0]: Document(page_content="foo"),
index_to_id[1]: Document(page_content="bar"),
index_to_id[2]: Document(page_content="baz"),
}
)
assert docsearch.docstore.__dict__ == expected_docstore.__dict__
output = docsearch.similarity_search("foo", k=1)
assert output == [Document(page_content="foo")]
def test_faiss_vector_sim() -> None:
"""Test vector similarity."""
texts = ["foo", "bar", "baz"]
docsearch = FAISS.from_texts(texts, FakeEmbeddings())
index_to_id = docsearch.index_to_docstore_id
expected_docstore = InMemoryDocstore(
{
index_to_id[0]: Document(page_content="foo"),
index_to_id[1]: Document(page_content="bar"),
index_to_id[2]: Document(page_content="baz"),
}
)
assert docsearch.docstore.__dict__ == expected_docstore.__dict__
query_vec = FakeEmbeddings().embed_query(text="foo")
output = docsearch.similarity_search_by_vector(query_vec, k=1)
assert output == [Document(page_content="foo")]
# make sure we can have k > docstore size
output = docsearch.max_marginal_relevance_search_by_vector(query_vec, k=10)
assert len(output) == len(texts)
def test_faiss_with_metadatas() -> None:
"""Test end to end construction and search."""
texts = ["foo", "bar", "baz"]
metadatas = [{"page": i} for i in range(len(texts))]
docsearch = FAISS.from_texts(texts, FakeEmbeddings(), metadatas=metadatas)
expected_docstore = InMemoryDocstore(
{
docsearch.index_to_docstore_id[0]: Document(
page_content="foo", metadata={"page": 0}
),
docsearch.index_to_docstore_id[1]: Document(
page_content="bar", metadata={"page": 1}
),
docsearch.index_to_docstore_id[2]: Document(
page_content="baz", metadata={"page": 2}
),
}
)
assert docsearch.docstore.__dict__ == expected_docstore.__dict__
output = docsearch.similarity_search("foo", k=1)
assert output == [Document(page_content="foo", metadata={"page": 0})]
def test_faiss_with_metadatas_and_filter() -> None:
texts = ["foo", "bar", "baz"]
metadatas = [{"page": i} for i in range(len(texts))]
docsearch = FAISS.from_texts(texts, FakeEmbeddings(), metadatas=metadatas)
expected_docstore = InMemoryDocstore(
{
docsearch.index_to_docstore_id[0]: Document(
page_content="foo", metadata={"page": 0}
),
docsearch.index_to_docstore_id[1]: Document(
page_content="bar", metadata={"page": 1}
),
docsearch.index_to_docstore_id[2]: Document(
page_content="baz", metadata={"page": 2}
),
}
)
assert docsearch.docstore.__dict__ == expected_docstore.__dict__
output = docsearch.similarity_search("foo", k=1, filter={"page": 1})
assert output == [Document(page_content="bar", metadata={"page": 1})]
def test_faiss_with_metadatas_and_list_filter() -> None:
texts = ["foo", "bar", "baz", "foo", "qux"]
metadatas = [{"page": i} if i <= 3 else {"page": 3} for i in range(len(texts))]
docsearch = FAISS.from_texts(texts, FakeEmbeddings(), metadatas=metadatas)
expected_docstore = InMemoryDocstore(
{
docsearch.index_to_docstore_id[0]: Document(
page_content="foo", metadata={"page": 0}
),
docsearch.index_to_docstore_id[1]: Document(
page_content="bar", metadata={"page": 1}
),
docsearch.index_to_docstore_id[2]: Document(
page_content="baz", metadata={"page": 2}
),
docsearch.index_to_docstore_id[3]: Document(
page_content="foo", metadata={"page": 3}
),
docsearch.index_to_docstore_id[4]: Document(
page_content="qux", metadata={"page": 3}
),
}
)
assert docsearch.docstore.__dict__ == expected_docstore.__dict__
output = docsearch.similarity_search("foor", k=1, filter={"page": [0, 1, 2]})
assert output == [Document(page_content="foo", metadata={"page": 0})]
def test_faiss_search_not_found() -> None:
"""Test what happens when document is not found."""
texts = ["foo", "bar", "baz"]
docsearch = FAISS.from_texts(texts, FakeEmbeddings())
# Get rid of the docstore to purposefully induce errors.
docsearch.docstore = InMemoryDocstore({})
with pytest.raises(ValueError):
docsearch.similarity_search("foo")
def test_faiss_add_texts() -> None:
"""Test end to end adding of texts."""
# Create initial doc store.
texts = ["foo", "bar", "baz"]
docsearch = FAISS.from_texts(texts, FakeEmbeddings())
# Test adding a similar document as before.
docsearch.add_texts(["foo"])
output = docsearch.similarity_search("foo", k=2)
assert output == [Document(page_content="foo"), Document(page_content="foo")]
def test_faiss_add_texts_not_supported() -> None:
"""Test adding of texts to a docstore that doesn't support it."""
docsearch = FAISS(FakeEmbeddings().embed_query, None, Wikipedia(), {})
with pytest.raises(ValueError):
docsearch.add_texts(["foo"])
def test_faiss_local_save_load() -> None:
"""Test end to end serialization."""
texts = ["foo", "bar", "baz"]
docsearch = FAISS.from_texts(texts, FakeEmbeddings())
temp_timestamp = datetime.datetime.utcnow().strftime("%Y%m%d-%H%M%S")
with tempfile.TemporaryDirectory(suffix="_" + temp_timestamp + "/") as temp_folder:
docsearch.save_local(temp_folder)
new_docsearch = FAISS.load_local(temp_folder, FakeEmbeddings())
assert new_docsearch.index is not None
def test_faiss_similarity_search_with_relevance_scores() -> None:
"""Test the similarity search with normalized similarities."""
texts = ["foo", "bar", "baz"]
docsearch = FAISS.from_texts(
texts,
FakeEmbeddings(),
relevance_score_fn=lambda score: 1.0 - score / math.sqrt(2),
)
outputs = docsearch.similarity_search_with_relevance_scores("foo", k=1)
output, score = outputs[0]
assert output == Document(page_content="foo")
assert score == 1.0
def test_faiss_invalid_normalize_fn() -> None:
"""Test the similarity search with normalized similarities."""
texts = ["foo", "bar", "baz"]
docsearch = FAISS.from_texts(
texts, FakeEmbeddings(), relevance_score_fn=lambda _: 2.0
)
with pytest.warns(Warning, match="scores must be between"):
docsearch.similarity_search_with_relevance_scores("foo", k=1)
def test_missing_normalize_score_fn() -> None:
"""Test doesn't perform similarity search without a normalize score function."""
with pytest.raises(ValueError):
texts = ["foo", "bar", "baz"]
faiss_instance = FAISS.from_texts(texts, FakeEmbeddings())
faiss_instance.relevance_score_fn = None
faiss_instance.similarity_search_with_relevance_scores("foo", k=2)