Compare pdfs with different versions in bulk

pdf_diff.py

# Dependencies: Python 3+, ImageMagick
from os import listdir, system, makedirs
from os.path import isfile, join, splitext
from multiprocessing import Pool
import errno
import argparse


def make_sure_path_exists(path):
    try:
        makedirs(path)
    except OSError as exception:
        if exception.errno != errno.EEXIST:
            raise


def convert(file):
    system("convert -density 150 ./{0}/{1} -quality 100 ./{0}_out/{2}-%d.png".format(file[1], file[0],
                                                                                     splitext(file[0])[0]))


def compare(file):
    system("compare ./{0}_out/{2} ./{1}_out/{2} ./compare_out/{2}".format(args.new, args.old, file))


def convert_all_pdfs_to_png():
    new_pdf_files = [[str(f), args.new] for f in listdir(args.new) if isfile(join(args.new, f))]
    old_pdf_files = [[str(f), args.old] for f in listdir(args.old) if isfile(join(args.old, f))]

    all_files = []
    all_files.extend(new_pdf_files)
    all_files.extend(old_pdf_files)

    for path in ["./{}_out".format(args.new), "./{}_out".format(args.old), "./compare_out"]:
        make_sure_path_exists(path)

    with Pool(8) as p:
        p.map(convert, all_files)


def compare_old_and_new_pngs():
    new_png_files = [str(f) for f in listdir("./{}_out".format(args.new)) if isfile(join("./{}_out".format(args.new), f))]
    old_png_files = [str(f) for f in listdir("./{}_out".format(args.old)) if isfile(join("./{}_out".format(args.old), f))]

    new_set = set(new_png_files)
    old_set = set(old_png_files)

    for png in new_set:
        if png in old_set:
            compare(png)
            new_png_files.remove(png)
            old_png_files.remove(png)

    if len(new_png_files) > 0:
        print("---------------------------")
        print("Images not processed in \"./{}\":".format(args.new))
        for png in new_png_files:
            print(png)

    if len(old_png_files) > 0:
        print("---------------------------")
        print("Images not processed in \"./{}\":".format(args.old))
        for png in old_png_files:
            print(png)


def run():
    print("Converting PDF files to PNG...")
    convert_all_pdfs_to_png()
    print("Done converting.")
    print("Comparing outputs from new and old...")
    compare_old_and_new_pngs()
    print("Done.")


parser = argparse.ArgumentParser(description='Compare different versions of pdfs and see the difference.')
parser.add_argument('--old', nargs='?', help='old pdfs folder', default="old")
parser.add_argument('--new', nargs='?', help='new pdfs folder', default="new")
args = parser.parse_args()

run()