def _limit_description_to_key(description):
    """Translate between the description of the Text widget and the corresonding
    key and value pos in the fitarg dictionary.

    Parameters
    ----------
    description : str
        The string describing the widget

    Returns
    --------
    key : string
    The key in the fitarg dictionary

    attr: (0, 1)
    The entry position in the value of the fitarg dictionary
    """
    # Splits parameter name and _min or _max off
    # attr is either min or max
    key, attr = description.split('_')
    # Add limit so its is the correct key for self.fitarg
    key = 'limit_' + key
    if attr == 'min':
        attr = 0
    elif attr == 'max':
        attr = 1
    else:
        raise NotImplementedError(
            "Uuups there is something wrong." \
            "attr was %s but min/max was expected" % attr
        )
    return key, attr