PDF添加水印以及防止被删除、防止编辑与打印

**PDF 添加水印及防止被删除、编辑与打印**

在实际的工作中，我们经常需要保护PDF文档免受未经授权的修改或使用。为此，添加水印并设置相关限制是非常有用的技巧。在本文中，我们将介绍如何使用Python和一些第三方库来实现PDF文档的水印添加以及防止被删除、编辑与打印。

### **所需库**

我们需要以下几个库：

* `PyMuPDF`：用于处理PDF文档* `fpdf`：用于生成PDF文档可以使用pip进行安装：

bashpip install pymupdf fpdf

from fitz import fitz # PyMuPDFdef add_watermark(pdf_path, watermark_text):
 """
 Adds a watermark to the PDF document.

 Args:
 pdf_path (str): The path to the PDF file.
 watermark_text (str): The text of the watermark.

 Returns:
 None """

 # Open the PDF file using PyMuPDF doc = fitz.open(pdf_path)

 # Create a new page with the watermark text page = doc.new_page(595,842) # A4 size # Set the font and size of the watermark text txt = page.add_text("Helvetica",72)
 txt.set_font_size(72)
 txt.set_text(watermark_text)

 # Save the updated PDF file doc.save(pdf_path, overwrite=True)

# Example usage:
add_watermark('input.pdf', 'Confidential')

from fitz import fitz # PyMuPDFdef prevent_deletion(pdf_path, password):
 """
 Prevents the PDF document from being deleted.

 Args:
 pdf_path (str): The path to the PDF file.
 password (str): The password for encryption.

 Returns:
 None """

 # Open the PDF file using PyMuPDF doc = fitz.open(pdf_path)

 # Encrypt the PDF file with a password doc.encrypt(password, use_128bit=True)

 # Save the updated PDF file doc.save(pdf_path, overwrite=True)

# Example usage:
prevent_deletion('input.pdf', 'password123')

from fitz import fitz # PyMuPDFdef prevent_editing(pdf_path, password):
 """
 Prevents the PDF document from being edited.

 Args:
 pdf_path (str): The path to the PDF file.
 password (str): The password for encryption.

 Returns:
 None """

 # Open the PDF file using PyMuPDF doc = fitz.open(pdf_path)

 # Encrypt the PDF file with a password and set options doc.encrypt(password, use_128bit=True, allowPrinting=False, allowModify=False)

 # Save the updated PDF file doc.save(pdf_path, overwrite=True)

# Example usage:
prevent_editing('input.pdf', 'password123')

from fitz import fitz # PyMuPDFdef prevent_printing(pdf_path, password):
 """
 Prevents the PDF document from being printed.

 Args:
 pdf_path (str): The path to the PDF file.
 password (str): The password for encryption.

 Returns:
 None """

 # Open the PDF file using PyMuPDF doc = fitz.open(pdf_path)

 # Encrypt the PDF file with a password and set options doc.encrypt(password, use_128bit=True, allowPrinting=False)

 # Save the updated PDF file doc.save(pdf_path, overwrite=True)

# Example usage:
prevent_printing('input.pdf', 'password123')