def col_num2text(df):
    """
    Funcito to convert categorical values represented by numbers
    to text to facilitate ohe

    Parameters
    ----------
    df : pandas data frame
        df befor conversion.

    Returns
    -------
    df : pandas data frame
        df after conversion.

    """
    df[['derived_msa_md', 'county_code',
        'hoepa_status', 'interest_only_payment', 'balloon_payment',
        'occupancy_type', 'applicant_sex',
        'lien_status', 'open_end_line_of_credit',
        'business_or_commercial_purpose'
        ]] = df[['derived_msa_md', 'county_code',
        'hoepa_status', 'interest_only_payment', 'balloon_payment',
        'occupancy_type', 'applicant_sex',
        'lien_status', 'open_end_line_of_credit',
        'business_or_commercial_purpose'
        ]].astype(str)
    return df