Problem running a python script (pypdf/hex errors)

I am trying to create a Python script using the PyPDF Module. What the script does it take the 'Root' folder, merges all the PDFs in it and outputs the merged PDF in an 'Output' folder and renames it to 'Root.pdf' (the folder which containes the split PDFs). What it does then is do the same with the sub-directories, giving the final output a name equal to the sub-directories.

I'm stuck when coming to process the sub-directories, giving me an error code related to some hex values. (it seems that it is getting a null value which is not in hex)

Here is the error code generated:

    Traceback (most recent call last):
  File "C:\Documents and Settings\student3\Desktop\Test\pdfMergerV1.py", line 76, in <module>
    files_recursively(path)
  File "C:\Documents and Settings\student3\Desktop\Test\pdfMergerV1.py", line 74, in files_recursively
    os.path.walk(path, process_file, ())
  File "C:\Python27\lib\ntpath.py", line 263, in walk
    walk(name, func, arg)
  File "C:\Python27\lib\ntpath.py", line 259, in walk
    func(arg, top, names)
  File "C:\Documents and Settings\student3\Desktop\Test\pdfMergerV1.py", line 38, in process_file
    pdf = PdfFileReader(file( filename, "rb"))
  File "C:\Python27\lib\site-packages\pyPdf\pdf.py", line 374, in __init__
    self.read(stream)
  File "C:\Python27\lib\site-packages\pyPdf\pdf.py", line 775, in read
    newTrailer = readObject(stream, self)
  File "C:\Python27\lib\site-packages\pyPdf\generic.py", line 67, in readObject
    return DictionaryObject.readFromStream(stream, pdf)
  File "C:\Python27\lib\site-packages\pyPdf\generic.py", line 531, in readFromStream
    value = readObject(stream, pdf)
  File "C:\Python27\lib\site-packages\pyPdf\generic.py", line 58, in readObject
    return ArrayObject.readFromStream(stream, pdf)
  File "C:\Python27\lib\site-packages\pyPdf\generic.py", line 153, in readFromStream
    arr.append(readObject(stream, pdf))
  File "C:\Python27\lib\site-packages\pyPdf\generic.py", line 69, in readObject
    return readHexStringFromStream(stream)
  File "C:\Python27\lib\开发者_如何学运维site-packages\pyPdf\generic.py", line 276, in readHexStringFromStream
    txt += chr(int(x, base=16))
ValueError: invalid literal for int() with base 16: '\x00\x00'

This is the source code for the script:

 #----------------------------------------------------------------------------------------------
# Name:        pdfMerger
# Purpose:     Automatic merging of all PDF files in a directory and its sub-directories and
#              rename them according to the folder itself. Requires the pyPDF Module
#
# Current:     Processes all the PDF files in the current directory
# To-Do:       Process the sub-directories.
#
# Version: 1.0
# Author:      Brian Livori
#
# Created:     03/08/2011
# Copyright:   (c) Brian Livori 2011
# Licence:     Open-Source
#---------------------------------------------------------------------------------------------
#!/usr/bin/env <strong class="highlight">python</strong>

import os
import glob
import sys
import fnmatch

from pyPdf import PdfFileReader, PdfFileWriter

output = PdfFileWriter()

path = str(os.getcwd())

x = 0

def process_file(_, path, filelist):
    for filename in filelist:
        if filename.endswith('.pdf'):

            filename = os.path.join(path, filename)
            print "Merging " + filename

            pdf = PdfFileReader(file( filename, "rb"))

            x = pdf.getNumPages()

            i = 0

            while (i != x):

                output.addPage(pdf.getPage(i))
                print "Merging page: " + str(i+1) + "/" + str(x)

                i += 1

                output_dir = "\Output\\"

                ext = ".pdf"
                dir =  os.path.basename(path)
                outputpath = str(os.getcwd()) + output_dir
                final_output = outputpath

                if os.path.exists(final_output) != True:

                                os.mkdir(final_output)
                                outputStream = file(final_output + dir + ext, "wb")
                                os.path.join(outputStream)
                                output.write(outputStream)
                                outputStream.close()

                else:

                                outputStream = file(final_output + dir + ext, "wb")
                                os.path.join(outputStream)
                                output.write(outputStream)
                                outputStream.close()

def files_recursively(topdir):
        os.path.walk(path, process_file, ())

files_recursively(path)

It looks like the PDF files you are reading are not valid PDF files, or they are more exotic than PyPDF is prepared for. Are you sure you have good PDF files to read?

Also, there are a few odd things in your code, but this one might really matter:

output_dir = "\Output\\"

You have a \O escape sequence there which isn't what you want.