def add_one_time_default(self, field, field_def):
        # OK, they want to pick their own one-time default. Who are we to refuse?
        print(" ? Please enter Python code for your one-off default value.")
        print(" ? The datetime module is available, so you can do e.g. datetime.date.today()")
        while True:
            code = raw_input(" >>> ")
            if not code:
                print(" ! Please enter some code, or 'exit' (with no quotes) to exit.")
            elif code == "exit":
                sys.exit(1)
            else:
                try:
                    result = eval(code, {}, {"datetime": datetime_utils})
                except (SyntaxError, __HOLE__) as e:
                    print(" ! Invalid input: %s" % e)
                else:
                    break
        # Right, add the default in.
        field_def[2]['default'] = value_clean(result)
dataset/ETHPy150Open cloudera/hue/desktop/core/ext-py/South-1.0.2/south/creator/actions.py/_NullIssuesField.add_one_time_default