Update app.py

app.py

@@ -1,8 +1,4 @@
-import os
-import re
-import validators
-import streamlit as st
-from dotenv import load_dotenv
+import os, re, validators, streamlit as st
 from youtube_transcript_api import YouTubeTranscriptApi, TranscriptsDisabled, VideoUnavailable
 from langchain.prompts import PromptTemplate
 from langchain.chains.summarize import load_summarize_chain
@@ -10,18 +6,24 @@ from langchain_groq import ChatGroq
 from langchain.schema import Document
 from langchain_community.document_loaders import UnstructuredURLLoader
 from langchain.document_loaders import PyPDFLoader
-from groq._base_client import APIConnectionError
-
-load_dotenv()
-GROQ_KEY = os.getenv("GROQ_API_KEY")
 
+# ─────────────────────────  STREAMLIT CONFIG  ──────────────────────────
 st.set_page_config(page_title="LangChain Summarizer", page_icon="🦜")
 st.title("🦜 LangChain: Summarize YT / Webpage / PDF")
 
-url_input = st.text_input("Paste a YouTube / web URL here:")
-file_input = st.file_uploader("…or upload a PDF", type=["pdf"])
+# ────────────────────────────  API KEY INPUT  ──────────────────────────
+with st.sidebar:
+    st.header("API keys")
+    groq_api_key = st.text_input("Groq API Key", type="password")
+    if groq_api_key:
+        os.environ["GROQ_API_KEY"] = groq_api_key          # for libraries
+
+# ─────────────────────  PLACEHOLDERS / FILE & URL INPUT  ───────────────
+generic_url   = st.text_input("Paste a YouTube / web URL here:")
+uploaded_file = st.file_uploader("…or upload a PDF", type=["pdf"])
 
-def get_video_id(url):
+# ──────────────────────────  UTILITY FUNCTIONS  ────────────────────────
+def get_video_id(url: str) -> str | None:
     m = re.search(r"(?:v=|\/)([0-9A-Za-z_-]{11})", url)
     return m.group(1) if m else None
 
@@ -30,57 +32,66 @@ SUMMARY_PROMPT = PromptTemplate(
     input_variables=["text"],
 )
 
-def build_llm():
+def build_llm() -> ChatGroq:
+    """Instantiate ChatGroq once and cache it in session_state."""
     if "llm" not in st.session_state:
-        if not GROQ_KEY:
-            raise RuntimeError("Missing GROQ_API_KEY")
-        st.session_state.llm = ChatGroq(model="deepseek-r1-distill-llama-70b", groq_api_key=GROQ_KEY)
+        st.session_state.llm = ChatGroq(
+            model="llama3-70b-8192",
+            groq_api_key=os.environ["GROQ_API_KEY"],
+        )
     return st.session_state.llm
 
 def summarize(docs):
-    llm = build_llm()
+    llm   = build_llm()
     chain = load_summarize_chain(llm, chain_type="stuff", prompt=SUMMARY_PROMPT)
     return chain({"input_documents": docs})["output_text"]
 
+# ─────────────────────────────  MAIN ACTION  ───────────────────────────
 if st.button("Summarize"):
-    if not GROQ_KEY:
-        st.error("Set GROQ_API_KEY in .env")
-    elif not url_input and not file_input:
-        st.error("Provide a URL or upload a PDF")
+    if not groq_api_key:
+        st.error("Please enter your Groq API key in the sidebar.")
+    elif not generic_url and not uploaded_file:
+        st.error("Provide a URL or upload a PDF, then press Summarize.")
     else:
         try:
             with st.spinner("Fetching and summarizing…"):
-                if file_input:
-                    tmp = f"/tmp/{file_input.name}"
-                    with open(tmp, "wb") as f:
-                        f.write(file_input.read())
-                    docs = PyPDFLoader(tmp).load()
-                    summary = summarize(docs)
-                    os.remove(tmp)
-                    st.success(summary)
-                elif "youtube" in url_input or "youtu.be" in url_input:
-                    vid = get_video_id(url_input)
+
+                # ---------- PDF ----------
+                if uploaded_file:
+                    tmp_path = f"/tmp/{uploaded_file.name}"
+                    with open(tmp_path, "wb") as f:
+                        f.write(uploaded_file.read())
+                    docs = PyPDFLoader(tmp_path).load()
+                    st.success(summarize(docs))
+                    os.remove(tmp_path)
+
+                # ---------- YouTube ----------
+                elif "youtube" in generic_url or "youtu.be" in generic_url:
+                    vid = get_video_id(generic_url)
                     if not vid:
-                        st.error("Couldn’t extract YouTube ID")
+                        st.error("Couldn’t extract a YouTube video ID 🤔")
                     else:
                         transcript = YouTubeTranscriptApi.get_transcript(vid)
                         text = " ".join(t["text"] for t in transcript)
-                        summary = summarize([Document(page_content=text)])
-                        st.success(summary)
+                        st.success(summarize([Document(page_content=text)]))
+
+                # ---------- Plain Webpage ----------
                 else:
-                    if not validators.url(url_input):
-                        st.error("Invalid URL")
+                    if not validators.url(generic_url):
+                        st.error("That doesn’t look like a valid URL.")
                     else:
                         docs = UnstructuredURLLoader(
-                            urls=[url_input],
+                            urls=[generic_url],
                             ssl_verify=False,
-                            headers={"User-Agent": "Mozilla/5.0"}
+                            headers={
+                                "User-Agent":
+                                "Mozilla/5.0 (X11; Linux) AppleWebKit/537.36 "
+                                "(KHTML, like Gecko) Chrome/121.0 Safari/537.36"
+                            },
                         ).load()
-                        summary = summarize(docs)
-                        st.success(summary)
+                        st.success(summarize(docs))
+
         except (TranscriptsDisabled, VideoUnavailable) as yt_err:
             st.error(str(yt_err))
-        except APIConnectionError:
-            st.error("Connection to Groq API failed. Check network and API key.")
         except Exception as e:
-            st.error(f"Unexpected error: {e}")
+            st.exception(e)