Update src/streamlit_app.py

src/streamlit_app.py

@@ -1,40 +1,55 @@
-import altair as alt
-import numpy as np
-import pandas as pd
 import streamlit as st
+import tempfile
+import os
+from nbconvert import HTMLExporter
+from nbformat import read, NO_CONVERT
+from weasyprint import HTML
 
-"""
-# Welcome to Streamlit!
-
-Edit `/streamlit_app.py` to customize this app to your heart's desire :heart:.
-If you have any questions, checkout our [documentation](https://docs.streamlit.io) and [community
-forums](https://discuss.streamlit.io).
-
-In the meantime, below is an example of what you can do with just a few lines of code:
-"""
-
-num_points = st.slider("Number of points in spiral", 1, 10000, 1100)
-num_turns = st.slider("Number of turns in spiral", 1, 300, 31)
-
-indices = np.linspace(0, 1, num_points)
-theta = 2 * np.pi * num_turns * indices
-radius = indices
-
-x = radius * np.cos(theta)
-y = radius * np.sin(theta)
-
-df = pd.DataFrame({
-    "x": x,
-    "y": y,
-    "idx": indices,
-    "rand": np.random.randn(num_points),
-})
-
-st.altair_chart(alt.Chart(df, height=700, width=700)
-    .mark_point(filled=True)
-    .encode(
-        x=alt.X("x", axis=None),
-        y=alt.Y("y", axis=None),
-        color=alt.Color("idx", legend=None, scale=alt.Scale()),
-        size=alt.Size("rand", legend=None, scale=alt.Scale(range=[1, 150])),
-    ))
+st.set_page_config(page_title="Colab Notebook → PDF", page_icon="📘", layout="centered")
+
+st.title("📘 Convert Jupyter / Colab Notebook to PDF")
+
+st.write(
+    "Upload your `.ipynb` file below and instantly download it as a **clean, readable PDF** — no LaTeX or setup needed!"
+)
+
+uploaded_file = st.file_uploader("Upload Notebook (.ipynb)", 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)
+
+        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)
+
+        # Convert HTML → PDF
+        HTML(html_path).write_pdf(pdf_path)
+
+        with open(pdf_path, "rb") as f:
+            st.download_button(
+                label="⬇️ Download PDF",
+                data=f,
+                file_name="notebook.pdf",
+                mime="application/pdf",
+            )
+
+        st.success("✅ Notebook successfully converted to PDF!")
+
+    except Exception as e:
+        st.error(f"❌ Conversion failed: {e}")