Update app.py

app.py

@@ -3,6 +3,7 @@ os.system("pip install streamlit pandas xlsxwriter openpyxl")
 
 import streamlit as st
 import pandas as pd
+from io import BytesIO
 
 st.set_page_config(page_title="Protein Repeat Comparator", layout="centered")
 st.title("🧬 Protein Repeat Comparator")
@@ -40,18 +41,20 @@ if uploaded_file1 and uploaded_file2:
         diff_df["Total Difference"] = diff_df.iloc[:, 2:].sum(axis=1)
         sorted_diff = diff_df.sort_values(by="Total Difference", ascending=False)
 
-        # Save to Excel
-        output_file = "protein_repeat_comparison.xlsx"
-        sorted_diff.to_excel(output_file, index=False)
+        # Save to in-memory buffer
+        output_buffer = BytesIO()
+        with pd.ExcelWriter(output_buffer, engine="openpyxl") as writer:
+            sorted_diff.to_excel(writer, index=False)
+        output_buffer.seek(0)
 
         st.success("✅ Comparison complete!")
-        with open(output_file, "rb") as f:
-            st.download_button(
-                label="📥 Download Comparison Excel",
-                data=f,
-                file_name=output_file,
-                mime="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
-            )
-
-    except Exception as e: 
-        st.error(f"⚠️ Error: {e}")
+        st.download_button(
+            label="📥 Download Comparison Excel",
+            data=output_buffer,
+            file_name="protein_repeat_comparison.xlsx",
+            mime="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
+        )
+
+    except Exception as e:
+        st.error(f"⚠️ Error: {e}")
+