Lint

libs/langchain/langchain/schema/runnable/utils.py

@@ -90,8 +90,10 @@ class IsFunctionArgDict(ast.NodeVisitor):
 class GetLambdaSource(ast.NodeVisitor):
     def __init__(self) -> None:
         self.source: Optional[str] = None
+        self.count = 0
 
     def visit_Lambda(self, node: ast.Lambda) -> Any:
+        self.count += 1
         if hasattr(ast, "unparse"):
             self.source = ast.unparse(node)
 
@@ -118,10 +120,11 @@ def get_lambda_source(func: Callable) -> Optional[str]:
     """
     try:
         code = inspect.getsource(func)
+        print(code)
         tree = ast.parse(textwrap.dedent(code))
         visitor = GetLambdaSource()
         visitor.visit(tree)
-        return visitor.source
+        return visitor.source if visitor.count == 1 else None
     except (SyntaxError, TypeError, OSError):
         return None
 

libs/langchain/tests/unit_tests/schema/runnable/test_runnable.py

@@ -2741,6 +2741,9 @@ async def test_runnable_branch_abatch() -> None:
     assert await branch.abatch([1, 10, 0]) == [2, 100, -1]
 
 
+@pytest.mark.skipif(
+    sys.version_info < (3, 9), reason="Requires python version >= 3.9 to run."
+)
 def test_reprsentation_of_runnables() -> None:
     """Test representation of runnables."""
     runnable = RunnableLambda(lambda x: x * 2)
@@ -2765,9 +2768,9 @@ def test_reprsentation_of_runnables() -> None:
             "b": RunnableLambda(lambda x: x * 3),
         }
     ) == (
-        "RunnableLambda(lambda x: x * 3)\n"
+        "RunnableLambda(...)\n"
         "| {\n"
         "    a: RunnableLambda(...),\n"
         "    b: RunnableLambda(...)\n"
         "  }"
-    )
+    ), "repr where code string contains multiple lambdas gives up"