Update src/streamlit_app.py

src/streamlit_app.py

@@ -1,55 +1,44 @@
 import streamlit as st
 import tempfile
+import subprocess
 import os
-from nbconvert import HTMLExporter
-from nbformat import read, NO_CONVERT
-from weasyprint import HTML
 
-st.set_page_config(page_title="Colab Notebook → PDF", page_icon="📘", layout="centered")
+st.set_page_config(page_title="Colab Notebook → PDF", page_icon="📘")
 
-st.title("📘 Convert Jupyter / Colab Notebook to PDF")
+st.title("📘 Colab Notebook → PDF Converter (LaTeX-based)")
 
-st.write(
-    "Upload your `.ipynb` file below and instantly download it as a **clean, readable PDF** — no LaTeX or setup needed!"
-)
+st.write("Upload your `.ipynb` notebook below to convert it to a PDF using LaTeX (nbconvert).")
 
-uploaded_file = st.file_uploader("Upload Notebook (.ipynb)", type=["ipynb"])
+uploaded_file = st.file_uploader("Upload your notebook", type=["ipynb"])
 
 if uploaded_file is not None:
     with tempfile.NamedTemporaryFile(delete=False, suffix=".ipynb") as tmp:
         tmp.write(uploaded_file.read())
         tmp_path = tmp.name
 
-    try:
-        # Convert to HTML using nbconvert (no LaTeX)
-        html_exporter = HTMLExporter()
-        html_exporter.exclude_input_prompt = True
-        html_exporter.exclude_output_prompt = True
-        html_exporter.template_name = "lab"  # cleaner modern layout
-
-        with open(tmp_path, "r", encoding="utf-8") as f:
-            notebook_node = read(f, as_version=NO_CONVERT)
-
-        body, _ = html_exporter.from_notebook_node(notebook_node)
+    st.info("🧩 Converting notebook to PDF... Please wait (1–2 min).")
 
-        html_path = tmp_path.replace(".ipynb", ".html")
-        pdf_path = tmp_path.replace(".ipynb", ".pdf")
-
-        with open(html_path, "w", encoding="utf-8") as f:
-            f.write(body)
+    try:
+        # Run nbconvert (LaTeX-based PDF export)
+        subprocess.run(
+            ["jupyter", "nbconvert", "--to", "pdf", tmp_path],
+            check=True,
+            stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE,
+        )
 
-        # Convert HTML → PDF
-        HTML(html_path).write_pdf(pdf_path)
+        pdf_file = tmp_path.replace(".ipynb", ".pdf")
 
-        with open(pdf_path, "rb") as f:
+        with open(pdf_file, "rb") as f:
             st.download_button(
                 label="⬇️ Download PDF",
                 data=f,
-                file_name="notebook.pdf",
+                file_name="converted_notebook.pdf",
                 mime="application/pdf",
             )
 
-        st.success("✅ Notebook successfully converted to PDF!")
+        st.success("✅ Conversion successful!")
 
-    except Exception as e:
-        st.error(f"❌ Conversion failed: {e}")
+    except subprocess.CalledProcessError as e:
+        st.error("❌ Conversion failed.")
+        st.exception(e)