fmt

libs/langchain/langchain/schema/runnable/base.py

@@ -51,6 +51,7 @@ Input = TypeVar("Input")
 # Output type should implement __concat__, as eg str, list, dict do
 Output = TypeVar("Output")
 Other = TypeVar("Other")
+R = TypeVar("R", bound="Runnable")
 
 
 class Runnable(Generic[Input, Output], ABC):
@@ -211,15 +212,18 @@ class Runnable(Generic[Input, Output], ABC):
         return RunnableBinding(bound=self, kwargs=kwargs)
 
     def with_fallbacks(
-        self,
+        self: R,
         fallbacks: Sequence[Runnable[Input, Output]],
         *,
         exceptions_to_handle: Tuple[Type[BaseException]] = (Exception,),
-    ) -> RunnableWithFallbacks[Input, Output]:
-        return RunnableWithFallbacks(
-            runnable=self,
-            fallbacks=fallbacks,
-            exceptions_to_handle=exceptions_to_handle,
+    ) -> R:
+        return cast(
+            R,
+            RunnableWithFallbacks(
+                runnable=self,
+                fallbacks=fallbacks,
+                exceptions_to_handle=exceptions_to_handle,
+            ),
         )
 
     """ --- Helper methods for Subclasses --- """
@@ -521,6 +525,9 @@ class RunnableWithFallbacks(Serializable, Runnable[Input, Output]):
     class Config:
         arbitrary_types_allowed = True
 
+    def __getattr__(self, item):
+        return getattr(self.runnable, item)
+
     @property
     def lc_serializable(self) -> bool:
         return True