How to Insert One PDF into Another Using PyPDF2 in Python

Introduction

During a study of a Python automation book, the author encountered a question about processing PDF files and decided to share a solution.

Approaches Considered

Three possible methods were outlined: (1) split two PDFs, sort, and merge; (2) use merge to insert pages directly (unsuccessful); (3) add pages one by one and save as a new file.

Chosen Solution

The third approach was selected as the simplest. It uses the PyPDF2 library, which must be installed via pip install PyPDF2. PyPDF2 can split, merge, encrypt, and extract PDF pages.

from PyPDF2 import PdfFileReader, PdfFileWriter

pdf_file1 = PdfFileReader("dogs_0.pdf")  # 要插入的pdf文件
pdf_file2 = PdfFileReader("python介绍.pdf")  # 要被插入的目标pdf文件
new_file = PdfFileWriter()

# 场景: 将 pdf_file1 插入到 pdf_file2 的第3页
new_file.addPage(pdf_file2.getPage(0))
new_file.addPage(pdf_file2.getPage(1))
new_file.addPage(pdf_file1.getPage(0))
new_file.addPage(pdf_file2.getPage(2))

# 写入文件
with open("merged_file.pdf", "wb") as f:
    new_file.write(f)

The code inserts the first page of dogs_0.pdf after the second page of python介绍.pdf and writes the result to merged_file.pdf. For many pages, a loop can automate the insertion.

Conclusion

The article demonstrates how to solve a practical PDF splitting and merging problem with PyPDF2, helping readers deepen their understanding of the library’s capabilities.