Python : split any file (binary) to different pieces and join them

This python program takes an input file and then splits it into different smaller chunks. Next it can collect all the different chunks and join it to get the original file.
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# 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() # read the entire content of the file
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()
f = open(fileName, 'wb')
for data in dataList:
f.write(data)
f.close()


# call the file splitting function

splitFile('1.mkv',110000000)

#call the function to join the splitted files
joinFiles('chunk',7,110000000)
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