Add neo4j graph environment variables (#12080)

libs/langchain/langchain/graphs/neo4j_graph.py

@@ -1,7 +1,8 @@
-from typing import Any, Dict, List
+from typing import Any, Dict, List, Optional
 
 from langchain.graphs.graph_document import GraphDocument
 from langchain.graphs.graph_store import GraphStore
+from langchain.utils import get_from_env
 
 node_properties_query = """
 CALL apoc.meta.data()
@@ -45,7 +46,11 @@ class Neo4jGraph(GraphStore):
     """
 
     def __init__(
-        self, url: str, username: str, password: str, database: str = "neo4j"
+        self,
+        url: Optional[str] = None,
+        username: Optional[str] = None,
+        password: Optional[str] = None,
+        database: str = "neo4j",
     ) -> None:
         """Create a new Neo4j graph wrapper instance."""
         try:
@@ -56,6 +61,11 @@ class Neo4jGraph(GraphStore):
                 "Please install it with `pip install neo4j`."
             )
 
+        url = get_from_env("url", "NEO4J_URI", url)
+        username = get_from_env("username", "NEO4J_USERNAME", username)
+        password = get_from_env("password", "NEO4J_PASSWORD", password)
+        database = get_from_env("database", "NEO4J_DATABASE", database)
+
         self._driver = neo4j.GraphDatabase.driver(url, auth=(username, password))
         self._database = database
         self.schema: str = ""

libs/langchain/tests/integration_tests/chains/test_graph_database.py

@@ -14,7 +14,7 @@ from langchain.llms.openai import OpenAI
 
 def test_connect_neo4j() -> None:
     """Test that Neo4j database is correctly instantiated and connected."""
-    url = os.environ.get("NEO4J_URL")
+    url = os.environ.get("NEO4J_URI")
     username = os.environ.get("NEO4J_USERNAME")
     password = os.environ.get("NEO4J_PASSWORD")
     assert url is not None
@@ -36,9 +36,22 @@ def test_connect_neo4j() -> None:
     assert output == expected_output
 
 
+def test_connect_neo4j_env() -> None:
+    """Test that Neo4j database environment variables."""
+    graph = Neo4jGraph()
+
+    output = graph.query(
+        """
+    RETURN "test" AS output
+    """
+    )
+    expected_output = [{"output": "test"}]
+    assert output == expected_output
+
+
 def test_cypher_generating_run() -> None:
     """Test that Cypher statement is correctly generated and executed."""
-    url = os.environ.get("NEO4J_URL")
+    url = os.environ.get("NEO4J_URI")
     username = os.environ.get("NEO4J_USERNAME")
     password = os.environ.get("NEO4J_PASSWORD")
     assert url is not None
@@ -68,7 +81,7 @@ def test_cypher_generating_run() -> None:
 
 def test_cypher_top_k() -> None:
     """Test top_k parameter correctly limits the number of results in the context."""
-    url = os.environ.get("NEO4J_URL")
+    url = os.environ.get("NEO4J_URI")
     username = os.environ.get("NEO4J_USERNAME")
     password = os.environ.get("NEO4J_PASSWORD")
     assert url is not None
@@ -102,7 +115,7 @@ def test_cypher_top_k() -> None:
 
 def test_cypher_intermediate_steps() -> None:
     """Test the returning of the intermediate steps."""
-    url = os.environ.get("NEO4J_URL")
+    url = os.environ.get("NEO4J_URI")
     username = os.environ.get("NEO4J_USERNAME")
     password = os.environ.get("NEO4J_PASSWORD")
     assert url is not None
@@ -146,7 +159,7 @@ def test_cypher_intermediate_steps() -> None:
 
 def test_cypher_return_direct() -> None:
     """Test that chain returns direct results."""
-    url = os.environ.get("NEO4J_URL")
+    url = os.environ.get("NEO4J_URI")
     username = os.environ.get("NEO4J_USERNAME")
     password = os.environ.get("NEO4J_PASSWORD")
     assert url is not None
@@ -178,7 +191,7 @@ def test_cypher_return_direct() -> None:
 
 def test_cypher_return_correct_schema() -> None:
     """Test that chain returns direct results."""
-    url = os.environ.get("NEO4J_URL")
+    url = os.environ.get("NEO4J_URI")
     username = os.environ.get("NEO4J_USERNAME")
     password = os.environ.get("NEO4J_PASSWORD")
     assert url is not None
@@ -243,7 +256,7 @@ def test_cypher_save_load() -> None:
     """Test saving and loading."""
 
     FILE_PATH = "cypher.yaml"
-    url = os.environ.get("NEO4J_URL")
+    url = os.environ.get("NEO4J_URI")
     username = os.environ.get("NEO4J_USERNAME")
     password = os.environ.get("NEO4J_PASSWORD")
     assert url is not None
@@ -267,7 +280,7 @@ def test_cypher_save_load() -> None:
 
 def test_exclude_types() -> None:
     """Test exclude types from schema."""
-    url = os.environ.get("NEO4J_URL")
+    url = os.environ.get("NEO4J_URI")
     username = os.environ.get("NEO4J_USERNAME")
     password = os.environ.get("NEO4J_PASSWORD")
     assert url is not None
@@ -307,7 +320,7 @@ def test_exclude_types() -> None:
 
 def test_include_types() -> None:
     """Test include types from schema."""
-    url = os.environ.get("NEO4J_URL")
+    url = os.environ.get("NEO4J_URI")
     username = os.environ.get("NEO4J_USERNAME")
     password = os.environ.get("NEO4J_PASSWORD")
     assert url is not None
@@ -347,7 +360,7 @@ def test_include_types() -> None:
 
 def test_include_types2() -> None:
     """Test include types from schema."""
-    url = os.environ.get("NEO4J_URL")
+    url = os.environ.get("NEO4J_URI")
     username = os.environ.get("NEO4J_USERNAME")
     password = os.environ.get("NEO4J_PASSWORD")
     assert url is not None