def value_or_filename(string):
    if (string == ''):
        return ''
    if (string[0] == '@'):
        filename = string[1:]
        try:
            with open(os.path.expanduser(filename)) as f:
                output = f.read()
        except IOError as e:
            raise argparse.ArgumentTypeError(('Unable to read file %s' % filename))
    else:
        output = string
    return output
def value_or_filename(string):
    if (string == ):
        return 
    if (string[0] == '@'):
        filename = string[1:]
        try:
            with open(os.path.expanduser(filename)) as f:
                output = f.read()
        except IOError as e:
            raise argparse.ArgumentTypeError(('Unable to read file %s' % filename))
    else:
        output = string
    return output