File Copying In Python

import os
#reading the source file from the standard input device i.e., keyboard
sourceFileName = input('Enter the Source filename: ')

#verifying the existence of the source file
fileExists = os.path.isfile(sourceFileName)

if not fileExists:
print(sourceFileName," does not exist")

else:
#logic for creating a duplicate file name with source filename ending with string _Duplicate_File
print(sourceFileName," is available for copying")
tempFileName = sourceFileName.split('.')
print(tempFileName)
print('The source filename is: ',tempFileName[0])
print('The source file extension is: ',tempFileName[1])

destinationFileName = tempFileName[0]+'_Duplicate_File.'+tempFileName[1]
print('The destination file name created is: ',destinationFileName)

#reading the source file contents through the source file object named as fileReadObject
fileReadObject = open(sourceFileName,'r')
sourceFileContents = fileReadObject.read()
#writing the source file contents in to the destination duplicate file
fileWriteObject = open(destinationFileName,'w')
fileWriteObject.write(sourceFileContents)
fileReadObject.close()
fileWriteObject.close()