Added MD5 checksum calculation class.

import hashlib

import os

import sys

class Checksum(object):

    def __init__(self):

        self.fileBufferSize = 4096

        self.md5FileSuffix = "-md5sum.txt"

    def setFileBufferSize(fileBufferSize):

        self.fileBufferSize = fileBufferSize

    def md5sum(self, filePath):

        md5Hash = hashlib.md5()

        with open(filePath, "rb") as f:

            for chunk in iter(lambda: f.read(self.fileBufferSize), b""):

                md5Hash.update(chunk)

        return md5Hash.hexdigest()      

    def recursive(self, folderPath):        

        for folder, subfolder, files in os.walk(folderPath, topdown = False):

            cwd = os.path.basename(folder)

            parent = os.path.dirname(folder)

            md5FilePath = os.path.abspath(parent) + '/' + cwd + self.md5FileSuffix

            if not os.path.exists(md5FilePath):

                if not files == []:

                    md5file = open(md5FilePath, 'w')                    

                    for file in files:

                        filePath = os.path.abspath(folder) + '/' + file

                        md5file.write(self.md5sum(filePath) + "  ./" + file + '\n')

                    md5file.close() 

script, folderName = sys.argv

md5calc = Checksum()

md5calc.recursive(folderName)