When run from a parent folder, this script combines all pdf files contained within subfolders, e.g., this is useful in combining platform-wise layout drawings.

fwpdf.py

#!/usr/bin/env python
# -*- coding: UTF-8 -*-
'''
2014 ckunte
'''
import os
import platform

platforms = os.walk('.').next()[1]
for platform in platforms:
    msg = 'echo "Processing ' + str(platform) + ' ..";'
    cdr = 'cd ' + str(platform) + ';'
    if platform.system() == 'Darwin':
        cmd = '/System/Library/Automator/Combine\ PDF\ Pages.action/Contents/Resources/join.py -o' + str(platform) + '-layout.pdf *.pdf;'
    else:
        cmd = 'gs -dBATCH -dNOPAUSE -sDEVICE=pdfwrite -sOUTPUTFILE=' + str(platform) + '-layout.pdf *.pdf;'
    os.system(msg + cdr + cmd)
pass

Clean up file and folder names: Be aware that the os.walk() will not pick-up folders with long file names. Folders (and preferably files) with long names will need to be renamed first into short names, which can be done using zmv as follows:

#!/usr/bin/env zsh
autoload -U zmv
# Safety first: Always use -n switch to test changes before commit.

# Clean up file names in subdirectories and remove special characters
zmv -n '(**/)(*)' '$1${2//[^A-Za-z0-9.-]/_}'

# Replace spaces in filenames and folders with a hyphen
zmv -n '* *' '$f:gs/ /-'