def log_file_name(ext=False):
script_name = os.path.splitext(os.path.basename(sys.argv[<NUM_LIT:0>]))[<NUM_LIT:0>]<EOL>val = script_name + "<STR_LIT:_>" + str(int(time.time())) + "<STR_LIT>"<EOL>if ext:<EOL><INDENT>val += "<STR_LIT:_>" + ext<EOL><DEDENT>val += "<STR_LIT>"<EOL>return val<EOL>
Function : Creates a logfile name, named after this script and includes the number of seconds since the Epoch.
           An optional extension can be specified to make the logfile name more meaningful regarding its purpose.
Args     : ext - The extension to add to the log file name to indicate its purpose, i.e. ERR for error messages.
Returns  : str.