how to write the test case for a path is exist or not using python code example

Example 1: python os if file exists

import os.path

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

Example 2: how to check if file exists pyuthon

import os
file_exists = os.path.exists("example.txt") # Returns boolean representing whether or not the file exists