bytesio to create zip file from png bytes, download it

app.py

@@ -73,18 +73,36 @@ def index():
             stylesheets=[CSS(string=read_css_file())]
         )
         doc = fitz.open(stream=pdf_data, filetype="pdf")
-        for page_index in range(len(doc)):
-            page = doc.load_page(page_index)
-            pix = page.get_pixmap(dpi=240)
 
-            # Convert the rendered image into PNG bytes
+        memory_file = io.BytesIO()
-            png_bytes = pix.tobytes("png")
 
-            # You can now send png_bytes to a response or store it in a DB
+        # Create the zip file in the buffer
-            print(f"Page {page_index} is {len(png_bytes)} bytes.")
+        with zipfile.ZipFile(memory_file, 'w', zipfile.ZIP_DEFLATED) as zf:
+            for page_index in range(len(doc)):
+                page = doc.load_page(page_index)
+                pix = page.get_pixmap(dpi=240)
+
+                # Convert the rendered image into PNG bytes
+                png_bytes = pix.tobytes("png")
+
+                # You can now send png_bytes to a response or store it in a DB
+                print(f"Page {page_index} is {len(png_bytes)} bytes.")
+                zf.writestr("SLIDES/{:04d}.png".format(page_index), png_bytes)
 
         doc.close()
 
+
+        # Crucial step: rewind the buffer position to the beginning so the file can be read for download
+        memory_file.seek(0)
+
+        # Send the in-memory file using Flask's send_file
+        return send_file(
+            memory_file,
+            mimetype='application/zip',
+            as_attachment=True,
+            download_name='downloaded_files.zip'  # Use download_name for modern Flask versions
+        )
+
         print(f"Reference: {reference}, Version: {version}, Text: {verse_text}, Error: {error}")
 
     return render_template('index.html', reference=reference, version=version, verse_html=verse_html, error=error)