Checking a file's existence

The os module could be used to check if a file exists in a specific directory. For example: We extensively made use of the write_file.txt file. Before opening this file to read or write, we could check the file's existence:

import os
if __name__ == "__main__":
    # Check if file exists
    if os.path.isfile('/home/pi/Desktop/code_samples/write_file.txt'):
        print('The file exists!')
    else:
        print('The file does not exist!')

In the preceding code snippet, we make use of the isfile() function, available with the os.path module. When a file's location is passed an argument to the function, it returns True if the file exists at that location. In this example, since the file write_file.txt exists in the code examples directory, the function returns True. Hence the message, The file exists is printed to the screen:

if os.path.isfile('/home/pi/Desktop/code_samples/write_file.txt'): 
    print('The file exists!') 
else: 
    print('The file does not exist!')