how to know a file exist or not in python code example

Example 1: how to check whether file exists in python

import os.path

if os.path.isfile('filename.txt'):
    print ("File exist")
else:
    print ("File not exist")

Example 2: python os if file exists

import os.path

if os.path.isfile('filename.txt'):
    print ("File exist")
else:
    print ("File not exist")