def get_name_for_predict_column(columns):
    """
    Get a unique name for predicted column.
    """
    # As of now, the predicted column will take the form
    # constant string + number

    # The constant string is fixed as '_predicted'
    k = '_predicted'
    i = 0
    # Try attribute name of the form "_id", "_id0", "_id1", ... and
    # return the first available name
    while True:
        if k not in columns:
            break
        else:
            k = '_predicted' + str(i)
        i += 1
    # Finally, return the column name
    return k