python如何修改文本PDF中的文字，不影响PDF中的排版

import PyPDF2

def modify_pdf_text(input_path, output_path, text_to_replace, replacement_text):
    with open(input_path, 'rb') as file:
        pdf = PyPDF2.PdfFileReader(file)
        total_pages = pdf.getNumPages()
        writer = PyPDF2.PdfFileWriter()

        for page_number in range(total_pages):
            page = pdf.getPage(page_number)
            content = page.extractText()
            modified_content = content.replace(text_to_replace, replacement_text)
            page.mergePage(modified_content)
            writer.addPage(page)

        with open(output_path, 'wb') as output_file:
            writer.write(output_file)

# 使用示例
input_pdf = 'input.pdf'
output_pdf = 'output.pdf'
text_to_replace = '原始文本'
replacement_text = '替换后文本'

modify_pdf_text(input_pdf, output_pdf, text_to_replace, replacement_text)