Human: check if file excists on harddrive. Assistant: 
Here is a Python function to check if file excists on harddrive

import os

def file_exists(filename):
    """
    Check if file exists on harddrive.
    """
    try:
        if os.path.isfile(filename):
            return True
        else:
            return False
    except OSError:
        return False

# Enter the filename
filename = "/home/rosey/Desktop/test.txt"

# Calling the function
print((file_exists(filename)))

#Example Output
# False

#Remember to inspect code for bugs.