Allow send list of str for the Prompt on openai demo endpoint /v1/completions (#323)

* allow str or List[str] for prompt

* Update vllm/entrypoints/openai/api_server.py
Co-authored-by: Zhuohan Li <zhuohan123@gmail.com>

---------
Co-authored-by: Zhuohan Li <zhuohan123@gmail.com>

vllm/entrypoints/openai/api_server.py

@@ -357,7 +357,11 @@ async def create_completion(raw_request: Request):
 
     model_name = request.model
     request_id = f"cmpl-{random_uuid()}"
-    prompt = request.prompt
+    if isinstance(request.prompt, list):
+        assert len(request.prompt) == 1
+        prompt = request.prompt[0]
+    else:
+        prompt = request.prompt
     created_time = int(time.time())
     try:
         sampling_params = SamplingParams(

vllm/entrypoints/openai/protocol.py

@@ -73,7 +73,7 @@ class ChatCompletionRequest(BaseModel):
 
 class CompletionRequest(BaseModel):
     model: str
-    prompt: str
+    prompt: Union[str, List[str]]
     suffix: Optional[str] = None
     max_tokens: Optional[int] = 16
     temperature: Optional[float] = 1.0