Update service_request.py

service_request.py

@@ -63,6 +63,10 @@ def create_signature(api_secret: str) -> str:
 
 
 async def async_service_request(source_str: str, source: np.ndarray, target: np.ndarray, api_key: str, api_secret: str) -> np.ndarray:
+
+    if not target or len(target) == 0:
+        return None
+    
     ssl_context = ssl.create_default_context()
 
     async with websockets.connect(
@@ -73,9 +77,9 @@ async def async_service_request(source_str: str, source: np.ndarray, target: np.
             "api_key": api_key,
             "signature": create_signature(api_secret),
         }
-        if source_str is not None:
+        if source_str and len(source_str) > 0:
             request_dict["source_str"] = source_str
-        elif source is not None:
+        elif source and len(source) > 0:
             request_dict["source"] = base64.b64encode(source.tobytes()).decode("utf-8")
         else:
             return None