Bug Fix (#221)

Quick bug fix for semantic similarity vector injection

langchain/prompts/example_selector/semantic_similarity.py

@@ -8,6 +8,11 @@ from langchain.prompts.example_selector.base import BaseExampleSelector
 from langchain.vectorstores.base import VectorStore
 
 
+def sorted_values(values: Dict[str, str]) -> List[Any]:
+    """Return a list of values in dict sorted by key."""
+    return [values[val] for val in sorted(values)]
+
+
 class SemanticSimilarityExampleSelector(BaseExampleSelector, BaseModel):
     """Example selector that selects examples based on SemanticSimilarity."""
 
@@ -26,13 +31,13 @@ class SemanticSimilarityExampleSelector(BaseExampleSelector, BaseModel):
 
     def add_example(self, example: Dict[str, str]) -> None:
         """Add new example to vectorstore."""
-        string_example = " ".join(example.values())
+        string_example = " ".join(sorted_values(example))
         self.vectorstore.add_texts([string_example], metadatas=[example])
 
     def select_examples(self, input_variables: Dict[str, str]) -> List[dict]:
         """Select which examples to use based on semantic similarity."""
         # Get the docs with the highest similarity.
-        query = " ".join(input_variables.values())
+        query = " ".join(sorted_values(input_variables))
         example_docs = self.vectorstore.similarity_search(query, k=self.k)
         # Get the examples from the metadata.
         # This assumes that examples are stored in metadata.
@@ -73,7 +78,7 @@ class SemanticSimilarityExampleSelector(BaseExampleSelector, BaseModel):
         Returns:
             The ExampleSelector instantiated, backed by a vector store.
         """
-        string_examples = [" ".join(eg.values()) for eg in examples]
+        string_examples = [" ".join(sorted_values(eg)) for eg in examples]
         vectorstore = vectorstore_cls.from_texts(
             string_examples, embeddings, metadatas=examples, **vectorstore_cls_kwargs
         )

tests/unit_tests/prompts/test_utils.py

@@ -0,0 +1,9 @@
+"""Test functionality related to prompt utils."""
+from langchain.prompts.example_selector.semantic_similarity import sorted_values
+
+
+def test_sorted_vals() -> None:
+    """Test sorted values from dictionary."""
+    test_dict = {"key2": "val2", "key1": "val1"}
+    expected_response = ["val1", "val2"]
+    assert sorted_values(test_dict) == expected_response