def check_characters(text):
    """
    Method used to check the digit and special
    character in a text.
    Parameters:
    -----------------
        text (string): Text to clean

    Returns:
    -----------------
        characters (dict): Dictionary with digit
                           and special characters

    """

    numerical, special = [[] for i in range(2)]

    for i in range(len(text)):

        if text[i].isalpha():
            pass

        elif text[i].isdigit():
            # adding only unique characters
            numerical = list(set(numerical + [text[i]]))

        elif not text[i].isspace():
            # adding only unique characters
            special = list(set(special + [text[i]]))

    characters = {
        "numerical": numerical,
        "special": special
    }

    return characters