import fitz  # Import PyMuPDF

def overlay_notes(original_pdf_path, notes_pdf_path, output_pdf_path):
    # Open the original and notes documents
    original_pdf = fitz.open(original_pdf_path)
    notes_pdf = fitz.open(notes_pdf_path)

    # Iterate through the pages and overlay notes onto the original
    for page_number in range(len(original_pdf)):
        original_page = original_pdf[page_number]
        if page_number < len(notes_pdf):  # Check if there's a corresponding notes page
            notes_page = notes_pdf[page_number]
            # Create a pixmap of the notes page with an alpha channel (transparency)
            pixmap = notes_page.get_pixmap(alpha=True)
            # Insert the pixmap onto the original page
            original_page.insert_image(original_page.rect, pixmap=pixmap)

    # Save the modified document to a new file
    original_pdf.save(output_pdf_path)

# File paths
original_pdf_path = '1.pdf'
notes_pdf_path = '2.pdf'
output_pdf_path = 'merged_output.pdf'

# Function call to overlay the notes
overlay_notes(original_pdf_path, notes_pdf_path, output_pdf_path)