When I run the following Python code, an error occurs. What should I do to get this code to run?
here is the code :

from PyPDF2 import PdfReader, PdfWriter

def merge_pdfs(pdf_list, output_pdf):
    pdf_writer = PdfWriter()
    
    for pdf in pdf_list:
        pdf_reader = PdfReader(pdf)
        
        for page in pdf_reader.pages:
            print(page)
            pdf_writer.add_page(page)
            
    with open(output_pdf, 'wb') as out_pdf:
        pdf_writer.write(out_pdf)
if __name__ == '__main__':
    pdf_files = ['2019.pdf', '2020.pdf']
    merge_pdfs(pdf_files, 'merged_output.pdf')

here is the error message：
enter image description here

python version 3.12.5