Merge pull request langchain-ai#2 from ivendrov/patch-1

Wrap prompt with "Human" and "Assistant" by default

langchain/llms/anthropic.py

@@ -83,21 +83,37 @@ def _llm_type(self) -> str:
         """Return type of llm."""
         return "anthropic"
 
-    def _call(self, prompt: str, stop: Optional[List[str]] = None) -> str:
+    def _call(self, prompt: str, stop: Optional[List[str]] = None, instruct_mode: Boolean = True) -> str:
         """Call out to Anthropic's completion endpoint.
+        
+        Will by default act like an instruction-following model, by wrapping the prompt with Human: and Assistant:
+        If you want to use for chat or few-shot, pass in instruct_mode=False
 
         Args:
             prompt: The prompt to pass into the model.
             stop: Optional list of stop words to use when generating.
+            instruct_mode: Whether to emulate an instruction-following model.
 
         Returns:
             The string generated by the model.
 
         Example:
             .. code-block:: python
 
-                response = anthropic("\n\nHuman: Tell me a joke.\n\nAssistant:", [])
+                response = anthropic("Tell me a joke.")
+                
+                response = anthropic("\n\nHuman: Tell me a joke.\n\nAssistant:", instruct_mode=False)
+
         """
+        if stop is None:
+            stop = []
+        # Never want model to invent new turns of Human / Assistant dialog.
+        stop.extend([anthropic.HUMAN_PROMPT, anthropic.AI_PROMPT])
+
+        if instruct_mode:
+            # Wrap the prompt so it emulates an instruction following model.
+            prompt = f"{anthropic.HUMAN_PROMPT} prompt{anthropic.AI_PROMPT} Sure, here you go:\n"
+
         response = self.client.completion(
             model=self.model, prompt=prompt, stop_sequences=stop, **self._default_params
         )