Update app.py

app.py

@@ -89,12 +89,13 @@ if uploaded_file:
                 buffer = io.StringIO()
                 df.to_csv(buffer, index=False)
                 buffer.seek(0)
+                bytes_data = io.BytesIO(buffer.getvalue().encode('utf-8'))
                 st.success("New visit entry added successfully!")
 
         # Download button (moved outside the form)
         st.download_button(
             label="Download Updated Data",
-            data=buffer,
+            data=bytes_data,
             file_name="updated_patient_data.csv",
             mime="text/csv"
         )
@@ -154,12 +155,13 @@ if uploaded_file:
                 buffer = io.StringIO()
                 df.to_csv(buffer, index=False)
                 buffer.seek(0)
+                bytes_data = io.BytesIO(buffer.getvalue().encode('utf-8'))
                 st.success("New patient account created successfully!")
 
         # Download button (moved outside the form)
         st.download_button(
             label="Download Updated Data",
-            data=buffer,
+            data=bytes_data,
             file_name="updated_patient_data.csv",
             mime="text/csv"
         )