A slight moderation to get the code working on http://bdurblg.blogspot.se/2011/06/python-split-any-file-binary-to.html (darn, need to get those indentations right...)

chunker.py

# define the function to split the file into smaller chunks
def splitFile(inputFile,chunkSize):
	#read the contents of the file
	f = open(inputFile, 'rb')
	data = f.read()
	f.close()

# get the length of data, ie size of the input file in bytes
	bytes = len(data)

#calculate the number of chunks to be created
	noOfChunks= bytes/chunkSize
	if(bytes%chunkSize):
		noOfChunks+=1

#create a info.txt file for writing metadata
	f = open('info.txt', 'w')
	f.write(inputFile+','+'chunk,'+str(noOfChunks)+','+str(chunkSize))
	f.close()



	chunkNames = []
	for i in range(0, bytes+1, chunkSize):
		fn1 = "chunk%s" % i
		chunkNames.append(fn1)
		f = open(fn1, 'wb')
		f.write(data[i:i+ chunkSize])
		f.close()



#define the function to join the chunks of files into a single file

def joinFiles(fileName,noOfChunks,chunkSize):

	dataList = []
	for i in range(0,noOfChunks,1):
		chunkNum=i * chunkSize
		chunkName = fileName+'%s'%chunkNum
		f = open(chunkName, 'rb')
		dataList.append(f.read())
		f.close()
	for data in dataList:
		f2 = open(fileName, 'wb')
		f2.write(data)
		f2.close()