Add "Search Only" to OpenAI model options and make OpenAI API key input optional

In this pull request, the following changes have been made:

1. Added "Search Only" to the options for the OpenAI model. This allows users to perform only a search without using the OpenAI model.

2. Made the input of the OpenAI API key optional. This allows the search to be executed even if the OpenAI API key is not entered.

These changes allow users to perform only a search without using the OpenAI model and to execute a search even if the OpenAI API key is not entered, improving user convenience.

Please review and let me know your thoughts.

app.py

@@ -1,23 +1,15 @@
-"""
-streamlit run app.py --server.address 0.0.0.0
-"""
-
 from __future__ import annotations
 
-import streamlit as st
 import os
-
-import faiss
-from sentence_transformers import SentenceTransformer
+import pandas as pd
 import torch
-from openai import OpenAI
+import faiss
 import streamlit as st
-import pandas as pd
-import os
 from time import time
+from openai import OpenAI
+from sentence_transformers import SentenceTransformer
+from datasets import load_dataset
 from datasets.download import DownloadManager
-from datasets import load_dataset  # type: ignore
-
 
 WIKIPEDIA_JA_DS = "singletongue/wikipedia-utils"
 WIKIPEDIA_JS_DS_NAME = "passages-c400-jawiki-20230403"
@@ -36,6 +28,7 @@ EMB_MODEL_NAMES = list(EMB_MODEL_PQ.keys())
 OPENAI_MODEL_NAMES = [
     "gpt-3.5-turbo-1106",
     "gpt-4-1106-preview",
+    "Search Only",
 ]
 
 E5_QUERY_TYPES = [
@@ -60,7 +53,6 @@ Responses must be given in Japanese.
 {question}
 """.strip()
 
-
 if os.getenv("SPACE_ID"):
     USE_HF_SPACE = True
     os.environ["HF_HOME"] = "/data/.huggingface"
@@ -68,9 +60,7 @@ if os.getenv("SPACE_ID"):
 else:
     USE_HF_SPACE = False
 
-# for tokenizer
 os.environ["TOKENIZERS_PARALLELISM"] = "false"
-
 OPENAI_API_KEY = os.environ.get("OPENAI_API_KEY")
 
 
@@ -81,6 +71,7 @@ def get_model(name: str, max_seq_length=512):
         device = "cuda"
     elif torch.backends.mps.is_available():
         device = "mps"
+
     model = SentenceTransformer(name, device=device)
     model.max_seq_length = max_seq_length
     return model
@@ -93,9 +84,7 @@ def get_wikija_ds(name: str = WIKIPEDIA_JS_DS_NAME):
 
 
 @st.cache_resource
-def get_faiss_index(
-    index_name: str, ja_emb_ds: str = WIKIPEDIA_JA_EMB_DS, name=WIKIPEDIA_JS_DS_NAME
-):
+def get_faiss_index(index_name: str, ja_emb_ds: str = WIKIPEDIA_JA_EMB_DS, name=WIKIPEDIA_JS_DS_NAME):
     target_path = f"faiss_indexes/{name}/{index_name}"
     dm = DownloadManager()
     index_local_path = dm.download(
@@ -110,9 +99,7 @@ def text_to_emb(model, text: str, prefix: str):
     return model.encode([prefix + text], normalize_embeddings=True)
 
 
-def search(
-    faiss_index, emb_model, ds, question: str, search_text_prefix: str, top_k: int
-):
+def search(faiss_index, emb_model, ds, question: str, search_text_prefix: str, top_k: int):
     start_time = time()
     emb = text_to_emb(emb_model, question, search_text_prefix)
     emb_exec_time = time() - start_time
@@ -121,7 +108,7 @@ def search(
     scores = scores[0]
     indexes = indexes[0]
     results = []
-    for idx, score in zip(indexes, scores):  # type: ignore
+    for idx, score in zip(indexes, scores):
         idx = int(idx)
         passage = ds[idx]
         results.append((score, passage))
@@ -133,7 +120,6 @@ def to_contexts(passages):
     for passage in passages:
         title = passage["title"]
         text = passage["text"]
-        # section = passage["section"]
         contexts += f"- {title}: {text}\n"
     return contexts
 
@@ -211,15 +197,13 @@ def app():
         key="question",
         value="楽曲『約束はいらない』でデビューした、声優は誰?",
     )
-    if not OPENAI_API_KEY:
-        st.text_input(
-            "OpenAI API Key",
-            key="openai_api_key",
-            type="password",
-            placeholder="※ OpenAI API Key 未入力時は回答を生成せずに、検索のみ実行します",
-        )
-    else:
-        st.session_state.openai_api_key = OPENAI_API_KEY
+    st.text_input(
+        "OpenAI API Key",
+        key="openai_api_key",
+        type="password",
+        value=OPENAI_API_KEY if OPENAI_API_KEY else "",
+        placeholder="※ OpenAI API Key 未入力時は回答を生成せずに、検索のみ実行します",
+    )
 
     with st.expander("オプション"):
         option_cols_main = st.columns(2)
@@ -229,6 +213,8 @@ def app():
             st.selectbox(
                 "OpenAI Model", OPENAI_MODEL_NAMES, index=0, key="openai_model_name"
             )
+        if "emb_model_name" not in st.session_state:
+            st.session_state.emb_model_name = EMB_MODEL_NAMES[0]  # replace with the actual default value you want to use
         emb_model_name = st.session_state.emb_model_name
         option_cols_sub = st.columns(2)
         with option_cols_sub[0]:
@@ -300,10 +286,10 @@ def app():
         st.dataframe(df, hide_index=True)
 
         openai_api_key = st.session_state.openai_api_key
-        if openai_api_key:
+        openai_model_name = st.session_state.openai_model_name
+        if openai_api_key and openai_model_name != "Search Only":
             openai_api_key = openai_api_key.strip()
             answer_header.subheader("Answer: ")
-            openai_model_name = st.session_state.openai_model_name
             temperature = st.session_state.temperature
             qa_prompt = st.session_state.qa_prompt
             max_tokens = st.session_state.max_tokens
@@ -320,4 +306,4 @@ def app():
 
 
 if __name__ == "__main__":
-    app()
+    app()