Check if path exists:
*Checking Path Existence and Permissions
os.F_OK | Value to pass as the mode parameter of access() to test the existence of path
os.R_OK | Value to include in the mode parameter of access() to test the readability of path
os.W_OK | Value to include in the mode parameter of access() to test the writeability of path
os.X_OK | Value to include in the mode parameter of access() to determine if path can be executed