Combine PDF's with specific names from two different folders using PyPDF2

I have two folders with a different set of pdfs. I know that the PDF with a specific name from the first folder needs to be combined with a PDF with a specific name from the second folder. For example, "PID-01.pdf" from the first folder needs to be combined with "FNN-PID-01.pdf" from the second folder, "PID-02.pdf" from the first folder needs to be combined with "FNN-PID-02.pdf" from the second folder, I have two folders with so on and so forth. I am using a python module PyPDF2. Could anyone give an example using PyPDF2

Solution

Did you mean "merged" as by saying "combined"?

if so,

lets say folder1 contains "PID-01.pdf" and folder2 contains "FNN-PID-01.pdf".

import os
from PyPDF2 import PdfFileMerger, PdfFileReader
folder1 = "/your/path/to/folder1/"
folder2 = "/your/path/to/folder2/"
merged_folder = "/your/path/to/merged/folder/"

f1_files = os.listdir(folder1) # ['PID-01.pdf','PID-02.pdf'...etc]
f2_files = os.listdir(folder2) # ['FNN-PID-01.pdf','FNN-PID-02.pdf'...etc]

def pdf_merger(f1,f2):
    merger = PdfFileMerger()
    f1_content = PdfFileReader(file(os.path.join(folder1,f1), 'rb'))
    f2_content = PdfFileReader(file(os.path.join(folder2,f2), 'rb'))
    merger.append(f1_content)
    merger.append(f2_content)
    out = os.path.join(merged_folder,f"merged-{f1}")
    merger.write(out)

#below code will iterate each file in folder1 and checks if those               
#folder2 filename string "FNN-PID-01.pdf" contains substring "PID-01.pdf"
#if matchs, the 2 matching files are merged and saved to merged_folder

for file1 in f1_files : 
    for file2 in f2_files: 
        if file1 in file2: 
            pdf_merger(file1,file2)

You can just iterate files and write your own matching pattern using regex for advanced usage.