Update app.py

app.py

@@ -1,22 +1,32 @@
 import gradio as gr
-from PyPDF2 import PdfReader, PdfWriter
+from PyPDF2 import PdfReader, PdfWriter, PageObject
 import tempfile
 import os
 import atexit
 
-def merge_pdfs(pdf_files, order):
+def merge_pdfs(pdf_files, order, start_on_odd=False):
     pdf_writer = PdfWriter()
     
     # Sort the PDF files based on the specified order, skipping files marked with '0'
     sorted_pdfs = [pdf_files[i-1] for i in order if i != 0]
     
+    # Define default page size (A4)
+    default_width = 595.276  # 8.27 inches
+    default_height = 841.890  # 11.69 inches
+    
     # Read and add each PDF file to the writer in the specified order
-    for pdf in sorted_pdfs:
+    for i, pdf in enumerate(sorted_pdfs):
         pdf_reader = PdfReader(pdf.name)
+        
+        # If start_on_odd is True and it's not the first PDF and the current total page count is odd, add a blank page
+        if start_on_odd and i > 0 and len(pdf_writer.pages) % 2 != 0:
+            blank_page = PageObject.create_blank_page(width=default_width, height=default_height)
+            pdf_writer.add_page(blank_page)
+        
         for page in pdf_reader.pages:
             pdf_writer.add_page(page)
     
-    # Create a named temporary file for the merged PDF as 'combine.pdf'
+    # Create a named temporary file for the merged PDF
     temp_file_path = os.path.join(tempfile.gettempdir(), "combine.pdf")
     with open(temp_file_path, 'wb') as temp_file:
         pdf_writer.write(temp_file)
@@ -25,14 +35,17 @@ def merge_pdfs(pdf_files, order):
 
 # Create Gradio interface
 with gr.Blocks() as demo:
-    gr.Markdown("# PDF Merger and Viewer")
+    gr.Markdown("# PDF Merger")
     pdf_input = gr.File(label="Upload PDF Files to Merge", file_types=[".pdf"], file_count="multiple")
     order_input = gr.Textbox(label="Enter the order of PDFs as comma-separated numbers, skip the number if you want to skip the file", placeholder="1,2,3,... or 3,1,2")
-    merge_button = gr.Button("Merge PDFs")
+    
+    with gr.Row():
+        merge_button = gr.Button("Merge PDFs (Normal)")
+        merge_odd_button = gr.Button("Merge PDFs (Each PDF starts on odd page)")
+    
     merged_result = gr.File(label="Download Merged PDF")
     
-    # Set button action to merge PDFs and then display the first page
-    def merge_and_preview(pdf_files, order):
+    def merge_and_preview(pdf_files, order, start_on_odd=False):
         n = len(pdf_files)
         
         if not order:
@@ -49,11 +62,21 @@ with gr.Blocks() as demo:
         if any(i < 0 or i > n for i in order):
             return gr.Error(f"Order values must be between 0 and {n} (0 means to skip the file).")
         
-        # Adjust order by removing '0' entries and merging only the specified files
-        merged_pdf_path = merge_pdfs(pdf_files, order)
+        # Merge PDFs with the specified start_on_odd option
+        merged_pdf_path = merge_pdfs(pdf_files, order, start_on_odd)
         return merged_pdf_path
     
-    merge_button.click(merge_and_preview, inputs=[pdf_input, order_input], outputs=[merged_result])
+    merge_button.click(
+        lambda *args: merge_and_preview(*args, False),
+        inputs=[pdf_input, order_input],
+        outputs=[merged_result]
+    )
+    
+    merge_odd_button.click(
+        lambda *args: merge_and_preview(*args, True),
+        inputs=[pdf_input, order_input],
+        outputs=[merged_result]
+    )
 
 # Launch the Gradio app
 demo.launch()
@@ -65,4 +88,4 @@ def cleanup_temp_files():
         if filename.endswith('.pdf'):
             os.remove(os.path.join(temp_dir, filename))
 
-atexit.register(cleanup_temp_files)
+atexit.register(cleanup_temp_files)