def get_fillna_dict(df: 'pd.DataFrame') ->dict:
    """ Generate a fillna dict for columns in a df
    """
    fillna_dict = {}
    for column in df:
        if df[column].dtype.kind in {'O', 'S'}:
            fillna_dict[column] = ''
        else:
            fillna_dict[column] = 0
    return fillna_dict
