fix duckduckgo rate limit

Author: billvsme

law_ai/retriever.py

@@ -10,6 +10,7 @@
 from langchain.text_splitter import RecursiveCharacterTextSplitter, TextSplitter
 from langchain.chains import LLMChain
 from langchain.retrievers.multi_query import MultiQueryRetriever
+from duckduckgo_search.exceptions import DuckDuckGoSearchException
 
 from .prompt import MULTI_QUERY_PROMPT_TEMPLATE
 from .utils import get_model
@@ -36,7 +37,10 @@ def _get_relevant_documents(
         run_manager: CallbackManagerForRetrieverRun,
     ) -> List[Document]:
 
-        results = self.search.results(query, self.num_search_results)
+        try:
+            results = self.search.results(query, self.num_search_results)
+        except DuckDuckGoSearchException:
+            results = []
 
         docs = []
         for res in results:

requirements.txt

@@ -2,5 +2,5 @@ langchain==0.0.319
 openai==0.28.1
 chromadb==0.4.14
 tiktoken==0.5.1
-duckduckgo-search==4.1.0
+duckduckgo-search==4.1.1
 gradio==3.50.0