Merge PDF Files using python PyPDF2

Question

I have watched a video to learn how to merge PDF files into one PDF file. I tried to modify a little in the code so as to deal with a folder which has the PDF files The main folder (Spyder) has the Demo.py and this is the code

import os
from PyPDF2 import PdfFileMerger

source_dir = os.getcwd() + './PDF Files'
merger = PdfFileMerger()

for item in os.listdir(source_dir):
    if item.endswith('pdf'):
        merger.append(item)

merger.write('.PDF Files/Output/Complete.pdf')       
merger.close()

I have a subfolder named PDF Files into the main folder Spyder and in this subfolder I put the PDF files and inside the subfolder PDF Files I created a folder named Output. I got error file not found as for the 1.pdf although when printing the item inside the loop, I got the PDF names.

The Traceback of error

Traceback (most recent call last):
  File "demo.py", line 9, in <module>
    merger.append(item)
  File "C:\Users\Future\AppData\Local\Programs\Python\Python36\lib\site-packages\PyPDF2\merger.py", line 203, in append
    self.merge(len(self.pages), fileobj, bookmark, pages, import_bookmarks)
  File "C:\Users\Future\AppData\Local\Programs\Python\Python36\lib\site-packages\PyPDF2\merger.py", line 114, in merge
    fileobj = file(fileobj, 'rb')
FileNotFoundError: [Errno 2] No such file or directory: '1.pdf'

Answer 1

I could solve it like that

import os
from PyPDF2 import PdfFileMerger

source_dir = './PDF Files/'
merger = PdfFileMerger()

for item in os.listdir(source_dir):
    if item.endswith('pdf'):
        #print(item)
        merger.append(source_dir + item)

merger.write(source_dir + 'Output/Complete.pdf')       
merger.close()

Answer 2

Shorter, faster stronger!

import glob
from PyPDF2 import PdfMerger

merger = PdfMerger()

for file in glob.glob('PDF_Folder/*.pdf'):
    merger.append(file)

merger.write('Complete.pdf')       
merger.close()