Merging pdf files using python

A term paper is due in a week. As part of research, I had to download a thesis, which was available in parts, as multiple pdf files. It becomes difficult to manage these in zotero, which I use to keep track of research and insert citations. so, learnt to combine pdf files using python. code below.

oh, first installed pyPDF2 - pip install pyPDF2

import PyPDF2 # this is the library for pdf mashing 
import os # module for management of files and directories  

# Create a PdfFileMerger object

merger = PyPDF2.PdfMerger()

# folder structure - pdfmerge/to-merge has the pdf files.
# Wanter to keep all pdf files to be merged in a folder.
# pdfmerge/ is where the .py file is. 

# Get list of pdf files from the folder into a list. 
path = "../pdfmerge/to-merge/"
file_names = os.listdir(path)

# directory name is added to each file name
string = "to-merge/"
paths_files = [string + x for x in file_names]
print(paths_files) #printing the file names just to check they are appearing in order

# Append each PDF to the merger
for pdf in paths_files:
    merger.append(pdf)

# Write out the merged PDF, the name of the target file can be anything. 
merger.write("result.pdf")
merger.close()